Court Opinion

ID: 6109503
Source: CourtListenerOpinion
Date Created: 2022-01-21 18:00:56.805501+00
Date Added: 2024-06-11T08:54:10.565882
License: Public Domain

FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                Nos. 19-10065
                Plaintiff-Appellee,           19-10420

                v.                          D.C. No.
                                         2:17-cr-00209-
RODNEY FLUCAS, AKA Rodney J.                 KJM-1
Flucas, AKA Rodney Rochea
Flucas, AKA Rodney Rochen
Flucas,                                    OPINION
             Defendant-Appellant.

     Appeal from the United States District Court
         for the Eastern District of California
  Kimberly J. Mueller, Chief District Judge, Presiding

       Argued and Submitted September 3, 2021
              San Francisco, California

                Filed January 21, 2022

Before: Mary M. Schroeder, Johnnie B. Rawlinson, and
            Jay S. Bybee, Circuit Judges.

            Opinion by Judge Rawlinson;
           Concurrence by Judge Schroeder;
               Dissent by Judge Bybee
2                   UNITED STATES V. FLUCAS

                            SUMMARY*

                               Criminal

    The panel affirmed convictions for transportation of a
minor with intent to engage in criminal sexual activity in
violation of 18 U.S.C. § 2423(a), and transportation of an
individual with intent to engage in criminal sexual activity in
violation of 18 U.S.C. § 2421(a).

    The defendant contended that he is entitled to a new trial
because the district court erroneously instructed the jury
concerning the requisite intent for transporting an individual
or minor for criminal sexual activity in violation of §§ 2421
or 2423. He maintained that the district court improperly
instructed the jury that he could be convicted if criminal
sexual activity was a motivating purpose of the transportation
of an individual, and that the district court was required to
instruct the jury that criminal sexual activity must be the
dominant purpose in order to establish the requisite intent.

    The panel held that the district court did not abuse its
discretion in instructing the jury, consistent with this court’s
precedent, that the government was required to prove beyond
a reasonable doubt that a dominant, significant, or motivating
purpose of the transportation of the defendant’s victims was
to engage in criminal sexual activity. The panel wrote that
the non-retroactive amendment to 18 U.S.C. § 2423(b), a
statute under which the defendant was not charged, does not
undermine the consistent precedent throughout the circuits

    *
      This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                 UNITED STATES V. FLUCAS                       3

rejecting the “dominant purpose” mens rea advocated by the
defendant.

    The panel addressed the defendant’s additional challenges
to his convictions in a concurrently filed memorandum
disposition.

    Concurring, Judge Schroeder wrote to underscore key
points that in her view undermine the dissent: (1) the dissent
views as binding language the Supreme Court used more than
seventy years ago in a case that raised different issues;
(2) courts have routinely treated “motivating” and
“significant” as interchangeable; and (3) one cannot assume
that the addition of “or motivating” to the instruction was
responsible for a second jury convicting after the first jury did
not.

    Dissenting, Judge Bybee wrote that no court has
considered whether “a motivating purpose” is different from
“a dominating or significant purpose,” and that in his view,
those terms are not synonymous. He wrote that the
instruction lowered the government’s burden of proof,
contrary to the holding in Mortensen v. United States,
322 U.S. 309 (1944), and this court’s Mann Act decisions;
and that the error is not harmless beyond a reasonable doubt.
4                 UNITED STATES V. FLUCAS

                          COUNSEL

Brian C. McComas (argued), Law Office of B.C. McComas
LLP, San Francisco, California, for Defendant-Appellant.

Veronica M.A. Alegria (argued), Assistant United States
Attorney; Camil A. Skipper, Appellate Chief; Phillip A.
Talbert, Acting United States Attorney; United States
Attorney’s Office, Sacramento, California; for Plaintiff-
Appellee.

                          OPINION

RAWLINSON, Circuit Judge:

    Rodney Flucas (Flucas) appeals his convictions for
transportation of a minor with intent to engage in criminal
sexual activity in violation of 18 U.S.C. § 2423(a), and
transportation of an individual with intent to engage in
criminal sexual activity in violation of 18 U.S.C. § 2421(a).
The evidence presented during a jury trial demonstrated that
Flucas sexually abused his daughters and other minors in his
household over several years, and was the father of numerous
children from his own daughters. The issue that confronts us
in this appeal is whether the district court properly instructed
the jury that it could convict Flucas if a motivating purpose
of his transportation of his victims from Oregon to California
was to engage in criminal sexual activity. Flucas maintains
that the district court was required to instruct the jury that the
government must prove beyond a reasonable doubt that the
dominant purpose of his transportation of his sexual abuse
victims was to engage in criminal sexual activity. Flucas
asserts that he was entitled to this instruction in support of his
                   UNITED STATES V. FLUCAS                           5

theory of defense that the dominant purpose of his
transportation of his victims from Oregon to California was
to obtain a higher paying job, not to engage in criminal sexual
activity.

    We have jurisdiction pursuant to 28 U.S.C. § 1291, and
we affirm Flucas’ convictions. We hold that the district court
did not abuse its discretion in instructing the jury, consistent
with our precedent, that the government was required to
prove beyond a reasonable doubt that a dominant, significant,
or motivating purpose of the transportation of Flucas’ victims
was to engage in criminal sexual activity.1

I. BACKGROUND

    In a third superseding indictment, Flucas was charged
with “knowingly transport[ing] in interstate commerce and
foreign commerce individuals Person 1, Person 2, and Person
3, each of whom had not attained the age of 18 years, with
intent that each such individual engage in sexual activity for
which any person could be charged with a criminal offense”
in violation of 18 U.S.C. § 2423(a). The indictment alleged
that Flucas engaged in incest, sexual intercourse, and oral
copulation with Person 1, Person 2, and Person 3 in violation
of California law. Flucas was also charged under 18 U.S.C.
§ 2421(a) with “knowingly transport[ing] in interstate
commerce and foreign commerce an individual, Person 4,
with intent that such individual engage in sexual activity for

    1
      In a memorandum disposition filed concurrently with this opinion,
we address Flucas’ additional challenges to his convictions.
6                   UNITED STATES V. FLUCAS

which any person could be charged with a criminal offense,
to wit: incest in violation of California Penal Code § 285.”2

    During Flucas’ second trial,3 Person 1 testified that, in
2014, she met Person 2, Flucas’ daughter, in Oregon, and
started living at Flucas’ residence. Person 1 stated that Flucas
was the father of her son, who was born in Stockton,
California, when Person 1 was sixteen years old. Person 1
related that Flucas started to “touch [her] in a sexual manner”
when she was fifteen years old, and had intercourse with her
between one and three times a week. Flucas instructed
Person 1 not to tell anyone about the sex acts, and to fabricate
a name for the father of her child.

    Flucas told Person 1 that he wanted her to move with him
to California in 2015 because she “was having his child.”
Flucas threatened Person 1, that if she attempted to stay in
Oregon with her father or stepmother, he would “bring [her]
back” to him. Person 1 did not believe that she “had a choice
about moving” to California. Person 1 testified that Flucas
continued to have intercourse “[a] few times a week” with her
in California. Person 1 did not believe that she “could stop
what was happening to [her].”

   Person 2, Flucas’ daughter, testified that Flucas started to
have intercourse with her when she was thirteen years old.
Person 2 became pregnant with Flucas’ child in 2013, when

    2
      A third count alleging that Flucas transported Person 2 and Person
3 with intent to engage in criminal sexual activity, was dismissed.
    3
      In Flucas’ first trial, the jury convicted Flucas of attempted witness
tampering, but was unable to reach a verdict on the transportation
offenses.
                 UNITED STATES V. FLUCAS                      7

she was fifteen years old, but lost the child. During an
investigation by child protective services, Person 2 did not
disclose the sexual abuse or that Flucas was the father of her
child. Prior to her interview, Flucas warned Person 2 that she
knew “what and what not to say.”

    Person 2 testified that she moved with Flucas to Klamath
Falls, Oregon, when she was fifteen years old, after he lost his
job in Americus, Georgia, due to allegations by “her little
sisters’ and brothers’ grandmother” of sexual abuse. They
relocated to Oregon because Flucas was “trying to move
away from . . . the people who were [making] the
allegations.” Person 2 related that Flucas continued to
sexually abuse her in Oregon.

    In 2017, Person 2 realized that she was unable to protect
her sisters, and decided that she “didn’t want to live
anymore.” Person 2 attempted to commit suicide by crashing
her car into a pole. At the hospital, Person 2 informed law
enforcement about the sexual abuse.

    Person 3, Flucas’ daughter, testified that Flucas started to
sexually abuse her when she was six years old, and had
intercourse with her for the first time when she was thirteen
years old. Flucas promised that he would purchase a cell
phone, computer, and car if she had intercourse with him.
Person 3 confirmed that Flucas continued to have intercourse
with her after moving to Oregon and California.

    Person 3 related that in 2017 she attempted to commit
suicide with “a bunch of [Flucas’] narcotics” because she
“didn’t want to be [in his house] anymore.” Person 3 testified
that she slept for most of the day until Flucas returned home.
Person 3 stated that, when Flucas returned, he took her into
8                UNITED STATES V. FLUCAS

a closet in his bedroom, where she vomited and they “had
sex.” When Person 3 was interviewed by child protective
services, Flucas told her to deny any sexual abuse.

    Person 4, Flucas’ daughter, testified that Flucas was the
father of her three children. Person 4 related that, in August,
2008, she was living with Flucas in Valdosta, Georgia. In
February, 2010, Flucas started to touch Person 4 “in a sexual
manner,” when she was in the ninth grade. Person 4 testified
that she was fifteen when Flucas began having intercourse
with her. Person 4 related that she was “confused,” and
became physically attracted to her father because he “made
[her] believe that [she] was the only one he wanted and . . . he
could take care of [her] and [her] kids.” Person 4 told her
sisters about the sexual abuse, but Flucas convinced them that
she was lying. Person 4 subsequently “covered up” her story
at Flucas’ insistence. Flucas also told Person 4 that he had
“recordings in the phones and cameras in the rooms to see
what you all are doing,” and commanded that “[w]hat
happens in this house stays in this house.”

    When Person 4 gave birth to her first child, Flucas told
her to fabricate the name of a father. Flucas also instructed
her not to provide the name of a father on the child’s birth
certificate. According to Person 4, Flucas told her that he
wanted to have “seven more kids” with her, and was angry
when she attempted to use birth control.

    In April, 2014, Person 4 was interviewed by the Georgia
Department of Family and Children’s Services. Person 4 lied
to the investigators when she told them that Flucas did not
sexually abuse her. Person 4 related that she subsequently
moved with Flucas and other members of his household to
Americus, Georgia, where they resided for approximately one
                 UNITED STATES V. FLUCAS                    9

month. Person 4 testified that it was Flucas’ idea to move to
Americus, and that he continued to have intercourse with her.

    Flucas was eventually fired from his job in Americus,
Georgia, when his employer was informed about sexual abuse
allegations. Flucas, Person 4, Person 4’s two children, Person
3, Person 2, and other members of the household
subsequently moved to Klamath Falls, Oregon, in September,
2014. Person 4 testified that Flucas would not allow her to
contact her mother to inform her where she was residing.
While in Oregon, Person 4 became pregnant with her third
child.

    Person 4 related that, in August, 2015, Flucas decided to
move to Stockton, California. Flucas prohibited Person 4
from contacting her mother. Flucas continued to have
intercourse with Person 4 in California. Flucas also told her
that, if she ever married, she “still [had to] have sex with
him.”

    Person 4 related that, after Person 2 was involved in an
accident, Flucas threatened Person 4 that, “If I go down you
go down. For every child you have, there’s like a three-year
sentence.” Person 4 was interviewed by a detective after
Person 2’s accident, and was confronted with DNA results
indicating that Flucas was the father of her children. As
directed by Flucas, Person 4 told the detective that she
“inseminated [herself] with a syringe” with semen from his
condoms.

   Person 4 testified that Flucas had intercourse with her on
October 28, 2017, at a hotel in California. According to
Person 4, Flucas told her that they could move to Switzerland,
Rhode Island, or New Jersey, where incest was legal.
10                  UNITED STATES V. FLUCAS

    Person 5 testified that her mother was in a relationship
with Flucas, and that Flucas sexually abused Person 5 when
she was eight years old. Flucas had intercourse with Person
5 for the first time when she was thirteen years old. Flucas
told Person 5 that she was “his soulmate,” and that, “if [she]
cheated on him, he’d kill [her].” Person 5 explained that she
was unable to tell anyone about the sexual abuse because she
didn’t think she would be believed. Person 5 eventually
thought she was “in love” with Flucas.

    Person 5 testified that Flucas was the father of her six
children. Flucas instructed Person 5 to fabricate the name of
a father for the children. Flucas also told Person 5 that he
wanted to have between eight and ten children with her.

    Person 5 moved with Flucas to Oregon in March, 2015,
when she was “eight or nine months pregnant.” Person 5
testified that Flucas continued to have intercourse with her in
Oregon. When they subsequently moved to Stockton,
California, Flucas prohibited Person 5 from informing her
mother. Flucas continued to have intercourse with Person 5
in California, and Person 5 became pregnant.

    When Person 5 was interviewed by a detective, she was
presented with DNA results indicating that Flucas was the
father of her children. Person 5 told the detective that she
inseminated herself with Flucas’ sperm because “that’s the
story that Mr. Flucas told [her] to say.”4

     4
      The dissent characterizes the evidence of Flucas’ guilty as “flimsy.”
Dissenting Opinion, p. 66. The dissent bases this characterization on
Flucas’ testimony that he moved to California for a better paying job. See
id. at 66. But this characterization does not acknowledge powerful
testimony from the victims detailing Flucas’ controlling behavior, his
                    UNITED STATES V. FLUCAS                            11

    Flucas testified that he had intercourse with Person 4, his
daughter, and acknowledged that sexual abuse occurred while
residing in Georgia. However, Flucas maintained that he
moved to California to seek a better paying job. Flucas’
defense was that he moved for financial reasons, not to
transport his daughters and the other minors for criminal
sexual activity.

    At trial, the government proposed the following
instruction with respect to the intent requirements for a
conviction under 18 U.S.C. § 2421 and 18 U.S.C. § 2423:

         To find the defendant guilty of Count One
         and/or Count Two, you need not find that the
         intended criminal sexual activity was the
         defendant’s sole or most important purpose.
         It is sufficient if the government proves
         beyond a reasonable doubt that the sexual
         activity was a significant, dominant, or
         motivating purpose. In other words, the
         government must prove that the criminal
         sexual activity was not merely incidental to
         the transportation. A person may have more
         than one significant, dominant, or motivating
         purpose for transporting others across a state
         line.

The government proposed the instruction because the jury in
Flucas’ first trial “struggled with the intent instruction and
asked for further clarifying instructions,” and the proffered

travels from other states where he was under investigation, and his refusal
to allow his victims to notify their relatives that they had moved.
12                   UNITED STATES V. FLUCAS

instruction “added clarity about the nature of the intent
instruction.”5

    Flucas objected to the proposed instruction because “it
[was] not sufficient for the government to prove that illegal
sexual activity was a motivating purpose,” and proposed an
alternative instruction:

         It is not necessary for the government to prove
         that the (prostitution or) illegal sexual activity
         was the sole purpose for any transportation
         from one state to another. A person may have
         several different purposes or motives for such
         travel and each may prompt in varying
         degrees the act of making the journey. The
         government must prove beyond a reasonable
         doubt, however, that a significant or dominant
         purpose of the travel from one state to another
         was to have the person(s) transported engage
         in (prostitution or) illegal sexual activity.

         The Government must prove that the criminal
         sexual activity was not merely incidental to
         the transportation.

    The district court determined that use of the term
“motivating” was consistent with legal precedent, and
instructed the jury that:

     5
      During Flucas’ first trial, the jury asked the district court to “clarify
the court’s definition of intent, beyond the instructions given.”
                   UNITED STATES V. FLUCAS                           13

         To find the defendant, Mr. Flucas, guilty of
         Count 1 and/or Count 2, you need not find
         that the intended criminal sexual activity was
         the defendant’s sole or most important
         purpose.

         It is sufficient if the government proves
         beyond a reasonable doubt that the sexual
         activity was a significant, dominant or
         motivating purpose.

         In other words, the government must prove
         that the criminal sexual activity was not
         merely incidental to the transportation.

         A person may have more than one significant
         dominant or motivating purpose for
         transporting others across a state line. To find
         Mr. Flucas guilty of Counts 1 and/or 2, the
         government must prove that Mr. Flucas
         intended Person 1, 2, 3 and/or 4 to engage in
         criminal sexual activity after transporting
         them from one state to another state, not that
         anyone actually engaged in such conduct.6

    6
      The dissent’s speculative assertion that “we must assume that [the
jury] chose the common denominator – ‘motivating’ – because satisfying
that standard would automatically satisfy the higher standards of
‘dominant’ and ‘significant’” is accompanied by no supporting authority.
Dissenting Opinion, p. 65.
14                  UNITED STATES V. FLUCAS

   The jury found Flucas guilty, and the district court
imposed a life sentence. Flucas filed a timely notice of
appeal.7

II. STANDARDS OF REVIEW

    “We review the formulation of jury instructions for abuse
of discretion, but review de novo whether those instructions
correctly state the elements of the offense and adequately
cover the defendant’s theory of the case. . . .” United States
v. Koziol, 993 F.3d 1160, 1179 (9th Cir. 2021) (citation and
internal quotation marks omitted).

III.       DISCUSSION

    Flucas contends that he is entitled to a new trial because
the district court erroneously instructed the jury concerning
the requisite intent for transporting an individual or minor for
criminal sexual activity in violation of 18 U.S.C. § 2421 and
18 U.S.C. § 2423. Flucas maintains that the district court
improperly instructed the jury that Flucas could be convicted
if criminal sexual activity was a motivating purpose of the
transportation of an individual, and that the district court was
required to instruct the jury that criminal sexual activity must
be the dominant purpose in order to establish the requisite
intent.

       7
       Because Flucas filed his notice of appeal on February 15, 2019,
“after the . . . announce[ment of] a . . . sentence” on February 12, 2019,
but “before the entry of the judgment” on February 25, 2019, his appeal
is “treated as filed on the date of and after the entry [of the judgment].”
Fed. R. App. P. 4(b)(2).
                 UNITED STATES V. FLUCAS                     15

    In interpreting the elements for transportation and travel
offenses, we have consistently held that a dominant,
significant, or motivating purpose to engage in criminal
sexual activity satisfies the intent requirement. In United
States v. Kinslow, 860 F.2d 963 (9th Cir. 1988), disapproved
of on other grounds by United States v. Brackeen, 969 F.2d
827, 829 (9th Cir. 1992) (en banc) (per curiam), we affirmed
the defendant’s conviction for “interstate transportation of a
minor for sexual purposes in violation of 18 U.S.C. § 2423.”
Id. at 964, 970. In rejecting the defendant’s assertion that
“the evidence was legally insufficient to support his
conviction . . . because sexual misconduct was not a dominant
purpose in the transportation of [the minor] across state
lines,” we responded that “[i]n this circuit, a federal crime
under 18 U.S.C. § 2423 exists if the immoral activity is one
of the dominant purposes of the transportation.” Id. at 967
(citation and internal quotation marks omitted). We further
emphasized that it was “not necessary . . . that the immoral
activity be the only purpose of the trip.” Id. Instead, we
concluded that:

       [The defendant] asserts that his only purpose
       in taking [the minor] across state lines was to
       insure his own safe passage from Arizona to
       California. While this may have been one of
       his goals, the jury was entitled to find that [the
       defendant] also intended to assert sexual
       control over the females in the . . . family and
       that this was one of the reasons he took them
       all into California. . . . A rational trier of fact
       could have found that one of the dominant
16                     UNITED STATES V. FLUCAS

            purposes in transporting [the minor] across
            state lines was to have her available to him for
            immoral, sexual purposes.

Id. at 967–98.

    In United States v. Lukashov, 694 F.3d 1107, 1110 (9th
Cir. 2012), we considered the defendant’s challenge to his
conviction for aggravated sexual abuse in violation of
18 U.S.C. § 2241(c).8 The defendant maintained that the
evidence supporting his conviction was insufficient because
“his purpose in traveling to New York and back to Oregon
was to pick up and deliver goods in his capacity as a
long-haul truck driver.” Id. at 1118. The district court
instructed the jury that:

            The government need not prove that the
            Defendant traveled across a state line for the
            sole and exclusive purpose of engaging in a
            sexual act. A person may have different
            purposes or motives for travel and each may

     8
         18 U.S.C. § 2241(c) provides in pertinent part:

            Whoever crosses a State line with intent to engage in a
            sexual act with a person who has not attained the age of
            12 years, . . . knowingly engages in a sexual act with
            another person who has not attained the age of 12 years,
            or knowingly engages in a sexual act under the
            circumstances described in subsections (a) [by force or
            threat] and (b) [by other means in a federal enclave]
            with another person who has attained the age of 12
            years but has not attained the age of 16 years (and is at
            least 4 years younger than the person so engaging), or
            attempts to do so, shall be fined under this title and
            imprisoned for not less than 30 years or for life.
                 UNITED STATES V. FLUCAS                    17

       prompt in varying degrees the act of making
       the journey. For purposes of this element, the
       government must prove beyond a reasonable
       doubt that a dominant, significant, or
       motivating purpose of Defendant’s travel
       across a state line was to engage in a sexual
       act with [the minor]. In other words, the
       government must prove the sexual act was not
       merely incidental to the travel.

Id. (alteration omitted) (emphasis added). Unpersuaded by
the defendant’s assertion that criminal sexual activity must be
the sole purpose for his travels, we held that:

       A rational jury could have found beyond a
       reasonable doubt that once [the defendant]
       formed the intent to sexually abuse [the
       minor], whether that occurred before he
       started the trip or only after he dropped off
       [another minor] in Montana and was alone in
       his truck with [his victim], he had that illicit
       intent for the rest of the trip, until he returned
       her to her mother in Portland. Given the
       repeated instances of abuse after the first time
       in Montana, a jury could rationally infer that
       [the defendant] crossed the Montana–North
       Dakota and subsequent state lines with a
       dominant, significant, or motivating purpose
       of committing additional sexual acts. That
       [the defendant] also had a commercial
       purpose for crossing state lines does not
       negate the inference that he had a significant
       or motivating purpose to continue abusing
       [the minor] because, as the district court
18               UNITED STATES V. FLUCAS

       correctly instructed the jury, the government
       did not have to prove that sexually abusing
       [the minor] was the sole purpose of [the
       defendant’s] interstate travel. . . .

Id. at 1118–19 (citation and internal quotation marks omitted)
(emphases added).

    In reaching this conclusion, we relied on the Tenth
Circuit’s decision in United States v. Cryar, 232 F.3d 1318
(10th Cir. 2000). See id. at 1119. In Cryar, the defendant
asserted that there was insufficient evidence supporting his
conviction for “cross[ing] the state line between Texas and
Oklahoma with the intent to engage in a sexual act with a
six-year old girl in violation of 18 U.S.C. § 2241(c).”
232 F.3d at 1319. The defendant specifically argued that “the
dominant purpose of his crossing the state line . . . was to
earn a living, and not to commit a sexual act.” Id. at 1324.
The Tenth Circuit disagreed, concluding that “there was
ample evidence for a jury to determine that a motivating or
dominant purpose of [the defendant’s] travels to Oklahoma
was to spend time with and attempt to engage in sexual acts
with a child under twelve years old.” Id. (citation omitted)
(emphasis added).

    In United States v. Lindsay, 931 F.3d 852, 864 (9th Cir.
2019), we applied Lukashov and rejected a challenge to a jury
instruction delineating the intent requirements for a
conviction under 18 U.S.C. § 2423. In that case, the district
court instructed the jury that:

       the United States does not have to prove that
       Defendant traveled in foreign commerce for
       the sole and exclusive purpose of engaging in
                 UNITED STATES V. FLUCAS                     19

       illicit sexual conduct. The government must
       prove that a dominant, significant, or
       motivating purpose of Defendant’s travel in
       foreign commerce was to engage in illicit
       sexual conduct.

Id. at 858 (internal quotation marks omitted) (emphasis
added). In addressing the defendant’s assertion that the
statutory term “‘for the purpose of’ clearly refers to a but-for
causation standard, contrary to the ‘dominant, significant, or
motivating’ standard the district court applied,” we clarified
that:

       It is not obviously wrong to interpret “for the
       purpose of” as applying to any dominant,
       significant, or motivating purpose to account
       for that fact, as a plain understanding of the
       phrase can encompass multiple intentions.
       For instance, in common conversation a
       person can travel to the grocery store “for the
       purpose of” buying milk and getting gas if
       both milk and gas are motivating reasons for
       the excursion.

Id. at 864 (emphasis added). In light of consistent precedent
that a motivating purpose to engage in illicit sexual activity
may support the intent requirements for transportation and
travel offenses, we held that “the district court did

not plainly err by instructing the jury that [the defendant]
traveled in foreign commerce for the purpose of engaging in
illicit sexual activity if that purpose was dominant,
significant, or motivating.” Id. (emphasis added). Although
we applied plain error review in rejecting the defendant’s
20               UNITED STATES V. FLUCAS

challenge to the jury instruction, we nonetheless adhered to
the principles articulated in Lukashov that the defendant’s
contention “ignore[d] the human ability and propensity to act
in light of multiple motives and purposes.” Id. at 864, quoting
Lukashov, 694 F.3d at 1118.

    The dissent minimizes the import of Lindsay because it
was decided on plain error review. See Dissenting Opinion,
pp. 55–56. Although “[a]n error cannot be plain where there
is no controlling authority on point and where the most
closely analogous precedent leads to conflicting results,”
United States v. Gnirke, 775 F.3d 1155, 1164 (9th Cir. 2015)
(citation and internal quotation marks omitted), that was not
the standard applied in Lindsay. Rather, we considered
Lukashov and concluded that it was not error to instruct the
jury regarding the defendant’s “motivating purpose.”
931 F.3d at 864. Notably absent was any mention of the lack
of “controlling authority” or conflicting precedent. Gnirke,
775 F.3d at 1164. In any event, in order for plain error to
exist, there must first be error. See United States v. Johnson,
979 F.3d 632, 636 (9th Cir. 2020), as amended. In Lindsay,
we found none. See Lindsay, 931 F.3d at 864.

    The dissent’s conclusion that there was no plain error in
Lindsay “[g]iven the confusion in the courts,” rests upon a
proposition which we never mentioned or relied on.
Dissenting Opinion, pp. 55–56. Rather, our holding that the
district court did not err in instructing the jury that a
dominant, significant, or motivating purpose suffices to
establish the requisite intent is bolstered by a long line of
consistent and uniform cases from our sister circuits.

    In United States v. Hayward, 359 F.3d 631 (3d Cir. 2004),
the defendant asserted that “the District Court should have
                 UNITED STATES V. FLUCAS                     21

instructed the jury that criminal sexual activity had to be ‘the
dominant’-rather than ‘a significant or motivating’-purpose
of the trip to England in order to convict.” Id. at 637
(emphases in the original). Instead, the district court
instructed the jury that:

       It is not necessary for the government to prove
       that the illegal sexual activity was the sole
       purpose for the transportation. A person may
       have several different purposes or motives for
       such travel, and each may prompt in varying
       degrees the act of making the journey. The
       government must prove beyond a reasonable
       doubt, however, that a significant or
       motivating purpose of the travel across state
       or foreign boundaries was to have the
       individual transported engage in illegal
       sexual activity. In other words, the illegal
       sexual activity must have not been merely
       incidental to the trip.

Id. (emphasis in the original). In approving the district
court’s instruction, the Third Circuit observed that:

       [The defendant] points to no case in which
       any Court of Appeals required a jury
       instruction that criminal sexual activity must
       be the dominant purpose of interstate travel to
       support a conviction under 18 U.S.C.
       § 2423(a). The Government relies on
       decisions by the First, Second, Fifth, Sixth,
       Seventh and Tenth Circuits, in which criminal
       sexual activity was one of a number of
       multiple motives for interstate travel. Those
22               UNITED STATES V. FLUCAS

       courts declined to reverse convictions where
       the respective district court had refused or
       failed to give “the dominant purpose” jury
       instruction that [the defendant] now requests.

Id. at 638 (citations omitted) (emphasis in the original).

    In United States v. Campbell, 49 F.3d 1079 (5th Cir.
1995), the Fifth Circuit similarly analyzed the intent
requirements for 18 U.S.C. § 2421 and 18 U.S.C. § 2423. See
id. at 1082. The defendant asserted that “the evidence was
insufficient to allow a reasonable jury to find that his
dominant purpose in traveling was to engage in prostitution.”
Id. (internal quotation marks omitted). The defendant
“question[ed] whether a dominant purpose can exist under the
Mann Act when an equally compelling but innocent purpose
for traveling exists,” and asserted that the prostitute’s “visit
was motivated at least equally by the desire to visit her
child.” Id. at 1083 (internal quotation marks omitted). The
Fifth Circuit rejected “this line of arithmetic hairsplitting,”
because “[t]he dominant requirement does not impose a but
for limitation on the defendant’s intent.” Id. (internal
quotation marks omitted). The Fifth Circuit explained that:

       In determining whether a dominant purpose
       exists, we instead ask whether the illicit
       behavior is one of the efficient and
       compelling purposes of the travel.
       Accordingly, many purposes for traveling
       may exist, but, as long as one motivating
       purpose is to engage in prostitution, criminal
       liability may be imposed under the Act. When
       no dominant purpose exists, it is because any
                 UNITED STATES V. FLUCAS                      23

        such purpose was either non-existent or
        incidental.

Id. (citations and internal quotation marks omitted) (emphasis
added). The Fifth Circuit concluded that “[w]hile it is true
that [the prostitute] did have a child in the area, and they
could have been traveling in order to visit the child, this fact
is not inconsistent with the prostitution plan. A reasonable
jury could find beyond a reasonable doubt that the group was
traveling to New Mexico to visit [the prostitute’s] daughter
and engage in prostitution.” Id. (emphasis in the original);
see also United States v. Hitt, 473 F.3d 146, 152 (5th Cir.
2006) (holding that evidence that the defendants “engage[d]
in a grooming process designed to reduce [the victim’s]
resistance to sexual advances” was sufficient to demonstrate
that the defendants “transported the victim to Louisiana with
an efficient and compelling purpose to engage in illicit sexual
activity”) (citations and internal quotation marks omitted).

    In United States v. Vang, 128 F.3d 1065 (7th Cir. 1997),
the Seventh Circuit, in affirming a conviction under
18 U.S.C. § 2423(b), explained that the evolving intent
standard for transportation and travel offenses originated with
the Mann Act. The Seventh Circuit observed that “[t]hough
enacted in 1994, the statutory antecedents of § 2423(b) date
back to the early part of this century.” Id. at 1069. “Congress
made the statute gender-neutral in a 1986 amendment, retired
the purpose test for interstate transportation, and clarified the
amorphous phrase any immoral purpose by narrowing the
statute’s coverage to illegal sexual activity.” Id. (footnote
reference and internal quotation marks omitted). “Section
2423 evolved from this same legislative initiative as an effort
to protect minors from predatory sexual conduct by adults,”
and “[i]n 1994, Congress created § 2423(b) in a further
24               UNITED STATES V. FLUCAS

attempt to expand the protection of minors. The new statute
punishes mere travel in interstate commerce—even if no
transportation of a minor was involved—if the defendant is
found to have traveled for the purpose of engaging in any
sexual act (as defined in another Code section) with a minor.”
Id.

    The Seventh Circuit concluded that the Supreme Court’s
statement in Mortensen v. United States, 322 U.S. 369 (1944)
that, under the Mann Act, illicit sexual activity “must be the
dominant motive of such interstate movement” was dicta. Id.
at 1071 (emphasis in the original). The Seventh Circuit
observed that “many circuits have upheld jury instructions
and convictions where an immoral purpose was at least one
of the purposes motivating the interstate transportation.” Id.
(citations and internal quotation marks omitted) (emphasis
added). “Other courts have used a dominant purpose
standard, but have regarded dominant as synonymous with
compelling or motivating, and they have never held—as
Defendants urge here—that interstate travel can have only
one dominant purpose.” Id. (citations and internal quotation
marks omitted). In approving the jury instruction provided by
the district court, the Seventh Circuit held that:

       the district court’s instructions to the jury
       interpreting § 2423(b)’s “purpose” element
       properly reflect this circuit’s law. At the most
       fundamental level, the defendants fail to
       convince us that Mortensen’s use of the word
       “dominant” grafted a new requirement onto
       the Mann Act that an immoral purpose must
       be “the dominant purpose” of interstate travel.
       Congress has not used the word “dominant” in
       either the Mann Act or § 2423(b), and we are
                 UNITED STATES V. FLUCAS                    25

       not prepared to read such a requirement into
       the statutes. . . . Courts . . . have consistently
       used the word “dominant” to mean merely
       “significant” or “compelling” or “efficient”;
       there has never been any implied requirement
       of preeminence of purpose. We are simply not
       willing to break ranks with our sister circuits
       on this matter for the sake of semantic purity.

Id. at 1072.

    In United States v. Perkins, 948 F.3d 936 (8th Cir. 2020),
the Eighth Circuit recently considered the intent requirements
for 18 U.S.C. § 2423(a) in discerning the mens rea for
violations of 18 U.S.C. § 2241(c). See id. at 937. The Eighth
Circuit explained that:

       The intent element of § 2241(c) is an issue of
       first impression for the Eighth Circuit. We
       have, however, addressed the intent element
       in cases involving the interstate transportation
       of a minor for the purpose of engaging in
       illegal sexual activity under 18 U.S.C.
       § 2423(a). To prove the intent element under
       § 2423(a), the illicit behavior must be one of
       the purposes motivating the interstate
       transportation, but need not be the dominant
       purpose, and the sexual activity just may not
       be merely incidental to the trip. The Eighth
       Circuit has also held intent for § 2423(a) may
       be inferred from all the circumstances,
       including the defendant’s own statements.
26               UNITED STATES V. FLUCAS

Id. at 938–39 (citations, alteration, and internal quotation
marks omitted) (emphasis added).

    Thus, a common analytical thread runs through our
precedent and that of other circuits for transportation
offenses—the requisite intent may be established when the
defendant has a dominant, significant, or motivating purpose
for transporting an individual in order to engage in criminal
sexual activity.

    The dissent basically advocates straying from this
precedential harmony to hold that the district court committed
instructional error as a matter of law. In its analytical
journey, the dissent initially relies on Hansen v. Haff,
291 U.S. 559, 562–63 (1934), a pre-World War II case, for
the proposition that “[p]eople not of good moral character,
like others, travel from place to place and change their
residence. But to say that, because they indulge in illegal or
immoral acts, they travel for that purpose, is to emphasize
that which is incidental and ignore what is of primary
significance.” Dissenting Opinion, p. 40. The dissent’s
reliance on this general language from Hansen does nothing
to diffuse the contemporary, consistent precedent underlying
the district court’s proper instruction.

    The dissent next lands on Mortensen v. United States,
322 U.S. 369 (1944), Cleveland v. United States, 329 U.S. 14
(1946), Hawkins v. United States, 358 U.S. 74 (1958), and
Daigle v. United States, 181 F.2d 311 (1st Cir. 1950) in
support of its contention that the defendant’s intent to illicit
sex acts not be “a mere incident but rather an efficient
purpose prompting and impelling the defendants to the
transportation of the girls.” Dissenting Opinion, pp. 42–43,
45–46. Our precedent and that of other circuits is consistent
                 UNITED STATES V. FLUCAS                      27

with this proposition, and also consistent with the instruction
given by the district court that the criminal sexual activity
could not be the “incidental purpose” of the defendant’s
travel or transportation for criminal sexual activity as distinct
from the travel. See Lukashov, 694 F.3d at 1118–19; Lindsay,
931 F.3d at 864; Hayward, 359 F.3d at 637; Campbell,
49 F.3d 1083; Perkins, 948 F.3d at 938–39.

    Importantly, in United States v. Ellis, 935 F.2d 385 (1st
Cir. 1991), the First Circuit took great pains to explain the
consistency among the holdings in Daigle, Mortensen, and
Hawkins, and the motivating purpose jury instruction:

        [The defendant] contends the court erred in
        rejecting his proffered alternative charge that
        the dominant purpose of the transportation
        must be the intent to engage in sexual activity
        with the minor. [The defendant] points to the
        Supreme Court’s holding in [Mortensen],
        construing an earlier Mann Act provision that
        preceded the present 18 U.S.C. § 2421. . . .

        Seven years after Mortensen, [in Daigle] this
        Circuit reviewed a district court’s instruction
        that the jury could convict so long as it found
        that one of the purposes of the interstate
        transportation was an immoral one.
        Notwithstanding Mortensen’s language on the
        dominant motive, we upheld the instruction.
        Both before 1950 and thereafter many other
        circuit courts took the same position, namely,
        that it was enough if one of the efficient
        purposes of the interstate transportation was
        to engage in the outlawed activity.
28            UNITED STATES V. FLUCAS

     [The defendant] urges us to reconsider Daigle
     as being inconsistent with the Supreme
     Court’s venerable pronouncements in
     Mortensen and elsewhere on dominant
     motive. We are not persuaded. Quite apart
     from the 40 years that have elapsed since
     Daigle, and its widespread acceptance, we
     believe Daigle’s reasoning to be sound and
     not inconsistent with Mortensen. As the
     Daigle court pointed out, there was in
     Mortensen a total lack of evidence of any
     purpose for the interstate journey other than
     the innocent one of giving the women a
     deserved vacation from their work as
     prostitutes in their bawdy house. Thus the
     Court had no reason to consider the question
     of multiple purposes. It is true that the
     language in Mortensen alluding to a single
     dominant purpose was repeated in a footnote
     in [Hawkins], but in Hawkins the Court was
     concerned with a very different issue. No
     more than Mortensen itself does Hawkins
     contradict Daigle on the narrow issue of
     interstate journeys involving several motives.

     In the present case, as in Daigle, the district
     court . . . sufficiently met the requirements of
     Mortensen, as interpreted in Daigle, by
     requiring that criminal sexual activity be one
     of the several motives or purposes not a mere
     incident of the trip or trips, but instead was at
     least one of the defendant’s motivations for
     taking the trip in the first place.
                 UNITED STATES V. FLUCAS                    29

Id. at 389–90 (citations, alterations, footnote reference, and
internal quotation marks omitted) (emphases in the original).

    The dissent also relies on a 1947 decision from the Eighth
Circuit, Mellor v. United States, 160 F.2d 757 (8th Cir. 1947).
See Dissenting Opinion, p. 45 n.2. However, the Eighth
Circuit has remained steadfast, as of 2020, in applying the
motivating purpose standard. See Perkins, 948 F.3d
at 938–39 (stating that “to prove the intent element under
§ 2423(a), the illicit behavior must be one of the purposes
motivating the interstate transportation, but need not be the
dominant purpose, and the sexual activity just may not be
merely incidental to the trip”) (citations, alteration, and
internal quotation marks omitted) (emphasis in the original).

    The dissent’s approach closely resembles the argument
advanced by the defendant and rejected by the Third Circuit
in Hayward. As the Third Circuit observed, “[the defendant]
points to no case in which any Court of Appeals required a
jury instruction that criminal sexual activity must be the
dominant purpose of interstate travel to support a conviction
under 18 U.S.C. § 2423(a).” 359 F.3d at 638 (footnote
reference omitted) (emphasis in the original). The Third
Circuit further emphasized the uniformity of the circuits on
this issue: the “First, Second, Fifth, Sixth, Seventh and Tenth
Circuits, in which criminal sexual activity was one of a
number of multiple motives for interstate travel . . . declined
to reverse convictions where the respective district court had
refused or failed to give the dominant purpose jury instruction
that [the defendant] now requests.” Id. (citations and internal
quotation marks omitted) (emphasis in the original).

    Against this backdrop of uniform precedent, the dissent
relies on United States v. Generes, 405 U.S. 93 (1972), “a tax
30               UNITED STATES V. FLUCAS

case” for which the dissent contends “the particulars are not
important to us.” Dissenting Opinion, p. 60. We disagree.
The “particulars” are important because they reveal the lack
of applicability of this tax case to the instruction given by the
district court in this criminal case.

    In Generes, “[a] debt a closely held corporation owed to
an indemnifying shareholder-employee became worthless in
1962.” Generes, 405 U.S. at 94. The issue was “whether, for
the shareholder-employee, that worthless obligation was a
business or a nonbusiness bad debt” under the Internal
Revenue Code and corresponding Treasury Regulations. Id.
The Treasury Regulation specified that “the character of the
debt is to be determined by the relation which the loss
resulting from the debt’s becoming worthless bears to the
trade or business of the taxpayer. If that relation is a
proximate one in the conduct of the trade or business in
which the taxpayer is engaged at the time the debt becomes
worthless, the debt comes within the exception provided by
that subparagraph.” Id. at 95 n.2 (alteration omitted)
(emphasis added). The Supreme Court explained that “[i]n
determining whether a bad debt is a business or a nonbusiness
obligation, the Regulations focus on the relation the loss bears
to the taxpayer’s business,” and that “[i]f, at the time of
worthlessness, that relation is a proximate one, the debt
qualifies as a business bad debt and the aforementioned
desirable tax consequences then ensue.” Id. at 95 (internal
quotation marks omitted). Resolution of the issue “turn[ed]
on the proper measure of the required proximate relation.”
Id.

    “At the trial Mr. Generes testified that his sole motive in
signing the indemnity agreement was to protect his
$12,000-a-year employment with the corporation,” and the
                   UNITED STATES V. FLUCAS                          31

district court instructed the jury that a “significant,” as
opposed to a “dominant” motivation, “satisfie[d] the
Regulations’ requirement of proximate relationship.” Id.
at 99 (footnote reference omitted).

    The Supreme Court “conclude[d] that in determining
whether a bad debt has a proximate relation to the taxpayer’s
trade or business, as the Regulations specify, and thus
qualifies as a business bad debt, the proper measure is that of
dominant motivation, and that only significant motivation is
not sufficient.” Id. at 103. In delineating the dominant
motivation standard for debts under the Tax Code and
Treasury Regulations, the Supreme Court stated in full9 that:

        The dominant-motivation standard has the
        attribute of workability. It provides a
        guideline of certainty for the trier of fact. The
        trier then may compare the risk against the
        potential reward and give proper emphasis to
        the objective rather than to the subjective. As
        has just been noted, an employee-shareholder,
        in making or guaranteeing a loan to his
        corporation, usually acts with two
        motivations, the one to protect his investment
        and the other to protect his employment. By
        making the dominant motivation the measure,
        the logical tax consequence ensues and
        prevents the mere presence of a business
        motive, however small and however
        insignificant, from controlling the tax result at
        the taxpayer's convenience. This is of

   9
     The dissent omits the highlighted language utilized by the Supreme
Court in articulating the standard. See Dissenting Opinion, p. 60.
32               UNITED STATES V. FLUCAS

       particular importance in a tax system that is so
       largely dependent on voluntary compliance.

Id. at 104 (emphasis added).

    There are notable distinctions between the standard
articulated in Generes and the standard applied to travel and
transportation offenses for criminal sexual activity. First, the
applicable Treasury Regulation, in defining nonbusiness debt,
“focus[ed] on the relation the loss bears to the taxpayer’s
business. If, at the time of worthlessness, that relation is a
proximate one, the debt qualifies as a business bad debt and
the aforementioned desirable tax consequences then ensue.”
Id. at 96. In contrast, the criminal statutes prohibiting
transportation of individuals and minors for criminal sexual
activity are not premised on a “proximate relation,” instead
establishing criminal liability for a defendant who “knowingly
transports any individual in interstate or foreign commerce,
or in any Territory or Possession of the United States, with
intent that such individual engage in prostitution, or in any
sexual activity for which any person can be charged with a
criminal offense,” 18 U.S.C. § 2421(a) (emphases added), or
who “knowingly transports an individual who has not attained
the age of 18 years in interstate or foreign commerce, or in
any commonwealth, territory or possession of the United
States, with intent that the individual engage in prostitution,
or in any sexual activity for which any person can be charged
with a criminal offense.” 18 U.S.C. § 2423(a) (emphases
added).

   Second, the Supreme Court developed the dominant
motivation standard in the tax context in order to prevent “the
mere presence of a business motive, however small and
however insignificant, from controlling the tax result at the
                 UNITED STATES V. FLUCAS                    33

taxpayer’s convenience.” Generes, 405 U.S. at 104. This
reasoning is consistent with the district court’s instruction
that “the government must prove that the criminal sexual
activity was not merely incidental to the transportation.”

   Third and finally, the Supreme Court emphasized that:

       The Code itself carefully distinguishes
       between business and non-business items. . . .
       The point . . . is that the tax statutes have
       made the distinction, that the Congress
       therefore intended it to be a meaningful one,
       and that the distinction is not to be obliterated
       or blunted by an interpretation that tends to
       equate the business bad debt with the
       nonbusiness bad debt.          We think that
       emphasis upon the significant rather than
       upon the dominant would have a tendency to
       do just that.

Id. at 103–04 (emphases added). The dissent does not point
to any similar distinctions intended by Congress in its efforts
to prohibit the transportation of minors and other individuals
for criminal sexual activity.

    Thus, the dissent ostensibly posits that the district court
should have imported the “dominant motivation” standard
used to determine a nonbusiness debt under the Treasury
Regulations to instruct the jury concerning the charges
brought against Flucas for transporting minors or other
individuals and engaging in criminal sexual activity. See
34                  UNITED STATES V. FLUCAS

Dissenting Opinion, p. 60. In light of Lukashov,10 Lindsay,
and consistent precedent from other circuits, we decline to
hold that the district court erred as a matter of law in not
instructing the jury based on the dissent’s formulation of a
standard applied in tax cases.

    Contrary to the dissent’s assertions, see Dissenting
Opinion, pp. 61–64, we are unconvinced that the non-
retroactive amendment to 18 U.S.C. § 2423(b), a statute
involving travel with intent to engage in illicit sexual conduct
that Flucas was not charged under, has any bearing on the
instructional issue raised in this appeal.11 Prior to December,
2018, 18 U.S.C. § 2423(b) provided that:

          A person who travels in interstate commerce
          or travels into the United States, or a United
          States citizen or an alien admitted for
          permanent residence in the United States who
          travels in foreign commerce, for the purpose
          of engaging in any illicit sexual conduct with
          another person shall be fined under this title
          or imprisoned not more than 30 years, or both.

18 U.S.C. § 2423(b)(2017) (emphasis added). In December,
2018, pursuant to the Abolish Human Trafficking Act of
2017, Congress amended 18 U.S.C. § 2423(b) in order to

     10
       The best argument that the dissent can muster against our reasoning
in Lukashov is that it was dicta. See Dissenting Opinion, p. 56. But dicta
or not, it was consistent with the other precedent approving the language
in the district court’s instruction.
     11
       The amendment to 18 U.S.C. § 2423(b) to specify “a motivating
purpose” standard has not been applied retroactively. See United States
v. Lieu, 963 F.3d 122, 126 n.1 (D.C. Cir. 2020).
                 UNITED STATES V. FLUCAS                    35

“combat sex tourism” by removing “for the purpose of” from
18 U.S.C. § 2423(b) and adding “with a motivating purpose”
in its place. Pub. L. 115-392, December 21, 2018, 132 Stat
5250, 5256.

    The Seventh Circuit’s discussion in United States v.
McGuire, 627 F.3d 622 (7th Cir. 2010) of the “purpose”
requirement for 18 U.S.C. § 2423(b), prior to the 2018
amendment, is instructive. In that case, the government only
charged the defendant with violating 18 U.S.C. § 2423(b).
The Seventh Circuit detailed the practical ramifications of the
government’s charging decision resulting from the statutory
distinctions:

       Section 2421 is the original Mann Act, as
       amended in minor respects. Section 2423(a),
       intended to protect minors from sexual
       predation, mirrors the Mann Act but imposes
       more severe penalties. Section 2423(b), the
       provision under which the defendant was
       prosecuted, was added to expand the
       protection of minors still further; it punishes
       travel in interstate commerce even if no minor
       is transported, if the purpose of the travel is
       sex with a minor. (Prosecutors frequently use
       this section to prosecute persons who cross
       state lines to rendezvous with minors whom
       they meet in online chat rooms). Section
       2423(c) was added to punish persons who
       travel in foreign commerce and have sex with
       a minor in the course of the trip regardless of
       what the defendant intended when he set out
       on it. It is apparent that if, as the jury found,
       the defendant had molested [the victim] on
36               UNITED STATES V. FLUCAS

       their travels, he violated sections 2421,
       2423(a), and 2423(c). But inexplicably the
       government charged the defendant only with
       violating section 2423(b), which requires that
       the travel be for the purpose of engaging in
       illegal sexual activity. This charging decision
       . . . enabled the defendant to argue that the
       purpose of his trips was merely to conduct
       retreats; sex was not the purpose but a
       welcome byproduct . . . of the opportunities
       that the retreats created, as the boys were
       more vulnerable when far from home and the
       defendant’s molestation of them was less
       likely to be detected by his religious
       superiors, who as we know had suspected him
       for many years of being a child molester yet
       had taken no effective steps to protect young
       boys from him.

Id. at 624 (citations omitted) (emphasis in the original).

    In its amended form, 18 U.S.C. § 2423(b) requires that the
government demonstrate that “a motivating purpose” of the
defendant’s travels was to engage in illicit sexual activity.
See 18 U.S.C. § 2423(b) (2021). It bears emphasizing that,
despite decades of precedent holding that a dominant,
significant, or motivating purpose may suffice to establish the
requisite intent for 18 U.S.C. § 2423(a), Congress did not
amend that statutory provision in any fashion. Notably,
18 U.S.C. § 2423(a), in stark contrast with the amended
version of 18 U.S.C. § 2423(b), does not use the term
“purpose,” instead providing that “[a] person who knowingly
transports an individual who has not attained the age of
18 years in interstate or foreign commerce, or in any
                 UNITED STATES V. FLUCAS                     37

commonwealth, territory or possession of the United States,
with intent that the individual engage in prostitution, or in
any sexual activity for which any person can be charged with
a criminal offense.” 18 U.S.C. § 2423(a) (emphasis added).
“We do not construe statutory phrases in isolation; we read
statutes as a whole, and where Congress includes particular
language in one section of a statute but omits it in another, it
is generally presumed that Congress acts intentionally and
purposely in the disparate inclusion or exclusion.”
Orozco-Lopez v. Garland, 11 F.4th 764, 776–77 (9th Cir.
2021) (citations, alterations, and internal quotation marks
omitted).

    In sum, we are not persuaded that the non-retroactive
2018 amendment to § 2423(b) has any bearing on whether the
district court abused its discretion in instructing the jury.
Rather, we conclude that the district court correctly instructed
the jury in accordance with our precedent and that of our
sister circuits with respect to the intent requirements under
18 U.S.C. §§ 2421(a) and 2423(a). After all, if Congress
wanted to also amend § 2423(a), it could have easily done so.

IV.    CONCLUSION

    The district court did not abuse its discretion in
instructing the jury concerning the intent requirements for
18 U.S.C. §§ 2421(a) and 2423(a). The instruction
comported with our precedent, as well as that of our sister
circuits, that the government must prove beyond a reasonable
doubt that a dominant, significant, or motivating purpose of
the transportation of the individuals was to engage in criminal
sexual activity. The non-retroactive amendment of a statute
that Flucas was not charged under does not undermine the
38               UNITED STATES V. FLUCAS

consistent precedent throughout the circuits rejecting the
“dominant purpose” mens rea advocated by Flucas.

     AFFIRMED.

SCHROEDER, Circuit Judge, concurring:

    This is not a complicated case. As Judge Rawlinson’s
opinion documents, the language in this instruction has been
provided to juries for decades and approved by appellate
courts. It required the jury to find that illegal sexual activity
was a “significant, dominant, or motivating purpose” of the
travel. I concur in Judge Rawlinson’s opinion but write
briefly only to underscore the key points that in my view
undermine the dissent.

    First, the dissent views as binding language the Supreme
Court used more than seventy years ago in a case that raised
different issues than those raised here. The statute here
requires interstate travel “with intent” to engage in unlawful
sexual activity. See 18 U.S.C. §§ 2421(a), 2423(a). The
Supreme Court’s opinion in Mortensen v. United States said
that such intent must be a “dominant motive” for the travel.
322 U.S. 369, 374 (1944). But the problem in Mortensen was
that the defendants had no intent to engage in unlawful
activities during their travel. See id. at 372. They were
taking a vacation from their business of running a brothel.
See id. That was “undisputed.” See id. The Court was
therefore not referring to any required quantum of unlawful
intent. The dissent thus fastens on to words that do not come
from a case where the defendant traveled with any unlawful
intent, much less from a case like this, where the defendant
                 UNITED STATES V. FLUCAS                     39

intended to engage in unlawful sex with members of his
household while moving them to a different state.

     Second, although the dissent acknowledges that the
instruction the parties agreed to was appropriate, the only
difference between that instruction and this one was the
addition of the phrase “or motivating” to the adjectives
“significant” and “dominant.” As the district court observed,
it is hard to see how the addition makes any difference, and
even harder to imagine how the jury would have understood
“motivating” as describing a materially lower standard than
“significant.” As the majority opinion demonstrates, courts
have routinely treated the words as interchangeable. That this
instruction has so long been given to juries without being
questioned in this way only underscores the lack of
perceptible difference between “dominant,” “significant,” and
“motivating.”

     Third, the dissent surmises that this jury likely did see a
difference because the first jury did not convict and the
second jury did. Even assuming the phrase was added
erroneously, we can not assume the addition could have been
responsible for the different result. Retrials differ from first
trials in many ways, only some of which might affect the
jury’s perceptions. Here, for example, in the second trial, the
government changed its presentation to concentrate on the
defendant’s activities during one time period rather than two.
The second jury thus heard a more focused presentation that
could have affected its understanding of the case. In contrast,
for the change in the wording of the instruction to have
possibly mattered, there would have to be some likelihood
that the jury shot a perceived gap between “significant” and
“motivating,” a gap neither the district judge, nor any other
judges reviewing similar instructions has ever thought
40                UNITED STATES V. FLUCAS

existed. The dissent is thus not supported by facts, semantics,
or precedent.

BYBEE, Circuit Judge, dissenting:

    Rodney Flucas is not a sympathetic defendant. There is
overwhelming evidence that Flucas groomed young girls for
sex, including his own daughters. He has fathered at least ten
children with these young women, making him the father of
his own grandchildren. Although he likely can be charged for
these acts in the states of Georgia, Oregon, and California, the
question in this case is whether Flucas has violated a federal
law, the Mann Act, 18 U.S.C. §§ 2421–24, for transporting
women and minors across state lines with the intent to engage
in criminal sexual activity. Flucas moved his family from
Oregon to California when he accepted a new, better-paying
position as a special education teacher in Stockton. But as the
Court trenchantly observed: “People not of good moral
character, like others, travel from place to place and change
their residence. But to say that, because they indulge in
illegal or immoral acts, they travel for that purpose, is to
emphasize that which is incidental and ignore what is of
primary significance.” Hansen v. Haff, 291 U.S. 559, 562–63
(1934).

    At Flucas’s first trial, the district court instructed the jury
that Flucas could be convicted only if the jury found that
“criminal sexual activity was one of the dominant purposes,
not merely an incidental purpose, for the transportation from
one state to another.” That jury hung and was dismissed. At
the second trial, the government requested a different
instruction, over Flucas’s objections. The district court
                UNITED STATES V. FLUCAS                   41

agreed to the instruction and told the jury it could convict
Flucas if “sexual activity was a significant, dominant, or
motivating purpose” for transporting the women across state
lines. The second time the jury convicted Flucas.

    The question before us is a linguistic one. No court has
considered whether “a motivating purpose” is different from
“a dominant or significant purpose.” In my view, those terms
are not synonymous.          The instruction lowered the
government’s burden of proof, contrary to the Supreme
Court’s decision in Mortensen v. United States, 322 U.S. 309
(1944), and our own Mann Act decisions; and the error in
instruction is not harmless beyond a reasonable doubt. Flucas
may be guilty of committing heinous acts in multiple
jurisdictions. But the government must show that his
dominant or significant purpose for traveling between those
jurisdictions was to commit those unlawful sexual acts. He
may or may not have done so. I respectfully dissent.

                              I

    In 1910, born out of a hysteria that “white slavers” were
preying upon young women—coercing them into prostitution
through threats, intimidation, and force—Congress passed
what is commonly called the Mann Act. See United States v.
Vang, 128 F.3d 1065, 1069–70 (7th Cir. 1997); David J.
Langum, Crossing Over the Line: Legislating Morality and
the Mann Act 3–4 (2006). Section 2 of the Act stated

       [A]ny person who shall knowingly transport
       or cause to be transported, or aid or assist in
       obtaining transportation for, or in
       transporting, in interstate or foreign
       commerce, or in any Territory or in the
42               UNITED STATES V. FLUCAS

       District of Columbia, any woman or girl for
       the purpose of prostitution or debauchery, or
       for any other immoral purpose, or with the
       intent and purpose to induce, entice, or
       compel such woman or girl to become a
       prostitute or to give herself up to debauchery,
       or to engage in any other immoral practice . . .
       shall be deemed guilty of a felony . . . .

White-Slave Traffic Act (Mann Act), Pub. L. No. 277, § 2, 36
Stat. 825 (1910) (emphasis added), current version at
18 U.S.C. § 2421. Alas, § 2 of the Mann Act used the term
“intent.” Intent is an important, perfectly good legal concept,
but sometimes in a statute, it is not particularly helpful. This
is one of those instances. The question is, what kind of intent
counts? The Mann Act isn’t clear on this point.

    The Supreme Court took up the question in Mortensen v.
United States, 322 U.S. 369 (1944). The Mortensens were
husband and wife who lived in Nebraska, where they ran a
house of prostitution. In 1940, they traveled by car to Salt
Lake City to visit family and national parks. They invited
two of the prostitutes they managed to accompany them on
the trip, and the girls accepted. No acts of prostitution
occurred along the route, nor while they were in Utah. When
the Mortensens and the two young women returned to
Nebraska, the girls resumed their sex trade. The United
States charged the Mortensens with violating the Mann Act
by transporting the girls in interstate commerce from Salt
Lake City to Nebraska for the purpose of engaging in
prostitution. The Court wrote that “[a]n intention that the
women or girls shall engage in the conduct outlawed by
Section 2 must be found to exist before the conclusion of the
interstate journey and must be the dominant motive of such
                    UNITED STATES V. FLUCAS                            43

interstate movement.” Id. at 374 (emphasis added). On that
basis, the Court overturned the conviction. Even “assum[ing]
that [the Mortensens] anticipated that the two girls would
resume their activities as prostitutes,” the “interstate vacation
trip . . . was [not] undertaken . . . for the purpose of, or as a
means of effecting or facilitating, such activities.” Id. at
374–75. According to the Court, “[w]hat Congress has
outlawed by the Mann Act, . . . is the use of interstate
commerce as a calculated means for effectuating sexual
immorality.” Id. at 375 (emphasis added). The Court
repeated its “dominant purpose” formulation in subsequent
Mann Act cases. See, e.g., Hawkins v. United States,
358 U.S. 74, 79 (1958) (“dominant purpose”); Cleveland v.
United States, 329 U.S. 14, 20 (1946) (“dominant motive”).

    The statute has been amended several times since
Mortensen. See Vang, 128 F.3d at 1069 (recounting the
history). The version Flucas was convicted under reads,
“[w]hoever knowingly transports any individual in interstate
or foreign commerce . . . with intent that such individual
engage in prostitution, or in any sexual activity for which any
person can be charged with a criminal offense, or attempts to
do so, shall be fined under this title or imprisoned not more
than 10 years, or both.” 18 U.S.C. § 2421(a).1 Despite
amendments that changed the Mann Act’s “intent and
purpose” language to “intent,” Mortensen continues to
influence our thinking in this area. But the Supreme Court’s
language in Mortensen has also caused great confusion.

    1
      Flucas was also convicted of violating 18 U.S.C. § 2423(a). The
language of § 2423(a) is substantially similar to § 2321(a), but applies to
transportation of minors.
44                UNITED STATES V. FLUCAS

                               A

    Federal courts since Mortensen have struggled with the
Court’s “dominant motive” formulation. Indeed, “courts turn
handsprings trying to define ‘dominant.’” United States v.
McGuire, 627 F.3d 622, 625 (7th Cir. 2010). For some time,
the courts debated whether Mortensen meant that the jury
must find that illicit sexual conduct was “the dominant
motive” or “a dominant motive” for the interstate
transportation. We were concerned that a person could have
more than one dominant purpose. The courts quickly agreed,
however, that people travel with mixed motives, and that so
long as “a dominant motive” was to traffic in prostitution or
another illegal criminal sex offense, the Mann Act was
satisfied. See, e.g., United States v. Drury, 582 F.2d 1181,
1185 (8th Cir. 1978) (prostitution must be “one of the
dominant purposes of such interstate travel”); United States
v. Snow, 507 F.2d 22, 24 (7th Cir. 1974) (“It now appears
settled that prostitution or other immoral conduct, need not be
the sole reason for the transportation . . . .”); United States v.
Salter, 346 F.2d 509, 511 (6th Cir. 1965) (“It is sufficient if
prostitution was only one of the dominant purposes.”);
Dingess v. United States, 315 F.2d 238, 240 (4th Cir. 1963)
(“If [the defendant] had some other lawful, but subordinate,
purpose which he also sought to serve, the existence of that
lawful purpose cannot purify or legitimize the dominant
purpose of prostituting his female companions.”); Dunn v.
United States, 190 F.2d 496, 497 (10th Cir. 1951) (“It is
enough that one of the dominant purposes was prostitution or
debauchery.”). See also Forrest v. United States, 363 F.2d
348, 350 (5th Cir. 1966).

   But the courts thought that the phrase “dominant motive”
was still confusing and began tinkering with alternative word
                      UNITED STATES V. FLUCAS                                45

formulas. Word formulas in statutes are typically Congress’s
effort to capture a “mood.” Universal Camera Corp. v.
NLRB, 340 U.S. 474, 487 (1951). Moods can be hard to
describe—a mood is itself “not . . . a body of rigid rules.” Id.
Nevertheless, “[a]s legislation that mood must be respected,
even if it can only serve as a standard for judgment.” Id. In
the case of the Mann Act, the federal courts tried to capture
Congress’s mood by adding their own word formulas. As I
demonstrate below, as we changed word formulas, we strayed
from Mortensen’s determination that the Mann act requires
engaging in illicit sexual activity play a dominant role in the
decision to travel between jurisdictions.

    In the aftermath of Mortensen, a number courts of appeals
looked to causation language borrowed from tort. They
variously required the government to prove that sex
trafficking was an “efficient purpose,” an “efficient and
compelling purpose,” or a “compelling and efficient
purpose.”2 See, e.g., Daigle v. United States, 181 F.2d 311,

     2
         The earliest use of “efficient purpose” in a published opinion
appears just two years after Mortensen. See United States v. Mellor, 71 F.
Supp. 53, 62 (D. Neb. 1946), aff’d, 160 F.2d 757 (8th Cir. 1947). The
district court in its explanation of the instruction referred to “efficient
purpose” as “explanatory causation.” 71 F. Supp. at 62. The related term
“efficient cause” has its origins in tort. See Jeremiah Smith, Legal Cause
in Actions of Tort, 25 Harv. L. Rev. 303 (1912). Professor Smith’s focus
was whether “the defendant’s tort [was] a substantial factor in producing
the damage complained of.” Id. at 310. He suggested that possible word
substitutes for “substantial” might include “efficient,” “continuously
efficient,” and “active and efficient” factor. Id. at 310 n.22. Anticipating
some of the developments here, he also suggested that “a substantial
factor” meant “[n]ot the sole factor, nor the predominant factor. Enough
if it is a substantial part of the causative antecedents; if it is one of several
substantial factors.” Id. at 311. See also Scott G. Johnson, The Efficient
Proximate Cause Doctrine In California: Ten Years After Garvey, 2 J. Ins.
46                 UNITED STATES V. FLUCAS

314 (1st Cir. 1950) (requiring the government to “prove that
the defendants’ immoral purpose was ‘not a mere incident but
rather an efficient purpose prompting and impelling the
defendants to the transportation of the girls.’” (quoting Mellor
v. United States, 160 F.2d 757, 764 (8th Cir. 1942)); Reamer
v. United States, 318 F.2d 43, 49 (8th Cir. 1963); United
States v. Campbell, 49 F.3d 1079, 1082 (5th Cir. 1995) (“It is
enough that one of the dominant purposes was prostitution or
debauchery. It suffices if one of the efficient and compelling
purposes in the mind of the accused in the particular
transportation was illicit conduct of that kind.” (emphasis
added) (quoting Forrest, 363 F.2d at 349); United States v.
Tyler, 424 F.2d 510, 512 (10th Cir. 1970) (“‘It is enough that
one of the purposes was prostitution. It suffices that one of
the efficient and compelling purposes in the mind of the
accused in a particular transportation was the prostitution
charged in the indictment.’”); United States v. Schneider,
801 F.3d 186, 194 (3d Cir. 2015) (“It now appears settled that
. . . immoral conduct, need not be the sole reason for the
transportation; the Act may be violated if [immoral conduct]
is a dominant or a compelling and efficient purpose.”
(alteration in original) (quoting United States v. Snow,
507 F.2 22, 24 (7th Cir. 1974)). In 1997, in an influential
opinion reviewing the Mann Act’s history and the cases, the
Seventh Circuit observed that “courts have used a “dominant
purpose’ standard but have regarded ‘dominant’ as
synonymous with ‘compelling’ or ‘motivating.’” Vang,
128 F.3d at 1071. The court concluded that “[c]ourts . . .
have consistently used the word ‘dominant’ to mean merely
‘significant’ or ‘compelling’ or ‘efficient.’” Inexplicably, it
further opined that “there has never been any implied

Coverage 1, 5–6 (1999) (noting that in tort “efficient proximate cause”
means “predominating cause”).
                 UNITED STATES V. FLUCAS                     47

requirement of preeminence of purpose.” Id. at 1072. See
also McGuire, 627 F.3d at 625.

    Although, prior to Vang, the phrase “motivating purpose”
had not appeared regularly in cases, it had been used by some
courts, usually in a casual way. See Campbell, 49 F.3d
at 1083. Around 2000, however, the phrase began to show up
more frequently. In United States v. Cryar, for example, the
district court had instructed the jury that the illegal sexual
conduct need not be the sole purpose for the travel, but was
sufficient under the Mann Act if it was “one of the
Defendant’s efficient and compelling purposes, or one of the
Defendant’s dominant purposes.” 232 F.3d 1318, 1324 (10th
Cir. 2000). The court of appeals affirmed the conviction and,
in the process, subtly altered the word formula. The court
commented that “there was ample evidence for a jury to
determine that a motivating or dominant purpose” for Cryar’s
travel was to engage in sexual conduct with a minor. Id.
(emphasis added). The language of “motivating purpose”
was the Tenth Circuit’s imprecise gloss on what the district
court had instructed.

    The Third Circuit followed suit, approving the addition of
“a motivating purpose” to jury instructions. In United States
v. Hayward, Hayward and his wife owned a competitive
cheerleading school and chaperoned six teenaged girls on a
trip to London. 359 F.3d 631 (3d Cir. 2004). While there,
Hayward plied them with alcohol and engaged in sexual
activity with them. At trial, Hayward argued that the jury
must find the illegal sexual conduct was “a dominant
purpose” for the trip. The district court declined and
instructed the jury that it was sufficient if the conduct was “a
significant or motivating purpose” of the trip to London. Id.
at 638 (emphasis added). On appeal, Hayward altered his
48               UNITED STATES V. FLUCAS

strategy and claimed that the only proper instruction was that
the trip had to be “the dominant purpose” for the trip. The
court rejected all of Hayward’s formulations, finding that the
jury instruction was proper. Id.

    Hayward’s emendation was picked up in a prominent
federal jury instruction treatise. In a section discussing the
Mann Act and citing Hayward as its authority, Modern
Federal Jury Instructions recommends the following
instruction for the intent element of 18 U.S.C. § 2421:

       In order to establish this element, it is not
       necessary for the government to prove that
       engaging in prostitution was the sole purpose
       for crossing the state line. A person may have
       several different purposes or motives for such
       travel, and each may prompt in varying
       degrees the act of making the journey. The
       government must prove beyond a reasonable
       doubt, however, that a significant or
       motivating purpose of the travel across a state
       line was that [said individual(s)] would
       engage in prostitution. In other words, that
       illegal activity must not have been merely
       incidental to the trip.

3 Leonard B. Sand, et al., Modern Federal Jury Instructions:
Criminal, ¶ 64.01, Instr. 64-4 (2021) (brackets in original).
The treatise blended two distinct concepts. The second
sentence quoted above uses “purposes” and “motives” as
nouns and treats them as synonyms. But the third sentence
converts “motive” to an adjective modifying “purpose.” As
a matter of syntax, the treatise can’t have it both ways.
Having suggested that “purposes” and “motives” are the
                    UNITED STATES V. FLUCAS                            49

same, a “motivating purpose” is redundant. It’s like saying
“purposeful purpose” or “motivating motive.”

    Confusion followed in the commentary. Modern Federal
Jury Instructions proposes that the illicit sexual activity does
not have to be “the dominant motive, but only that it be a
dominant motive in that it was a compelling or significant
motivation for the travel.” Id. ¶ 64.01, Instr. 64-4, Comment
(emphasis added). That statement would accurately capture
the pre-2000 consensus. The problem is that between the
model instruction and the commentary, the treatise uses
“significant purpose,” “motivating purpose,” “compelling
motivation,” and “significant motivation” as equivalents. The
inconsistency is not explained.3 Modern Federal Jury
Instructions has found its way into district court instructions
and been approved by at least one court of appeals. United
States v. An Soon Kim, 471 F. App’x. 82, 84 (2d Cir. 2012)
(quoting the district court’s instructions, which quote from
Modern Federal Jury Instructions, and citing the treatise with
approval).

    3
      Compounding its own confusion, in the same paragraph, the treatise
also favors eliminating use of the word “dominant” and the phrase
“efficient and compelling purpose” in instructions because they are
“likely to confuse the jury.” But, the treatise proposes using “the clearer
terms ‘sole purpose’ and ‘significant or motivating purpose,’ which are
easier to understand.” Modern Federal Jury Instructions: Criminal,
¶ 64.01, Instr. 64-4, Comment. Thus, in the same paragraph, the treatise
proposes that courts may use “significant motivation,” “motivating
purpose,” or “significant purpose” interchangeably, without any
explanation of how those phrases are equivalent.
50                   UNITED STATES V. FLUCAS

                                     B

    Our own precedent on the proper jury instruction in a
Mann Act case has followed a similar twisted path. We first
grappled with Mortensen’s “dominant motive” in Langford
v. United States, 178 F.2d 48 (9th Cir. 1949).4 Langford had
acted as Jones’s pimp. Eventually Langford asked Jones to
marry him, although he told her she would have to continue
to engage in prostitution. Jones and Langford traveled to
Tijuana to be married, after which they returned to Los
Angeles where Jones resumed her prostitution. Citing
Mortensen, we held that there was sufficient evidence that
“[Langford’s] dominant motive” for the marriage was to get
control of Jones and re-establish a relationship of pander and
prostitute. . . and that the trip, marriage and all, had that
primary end in view.” Id. at 52. See also Powell v. United
States, 347 F.2d 156, 157 (9th Cir. 1965) (“The trial court
properly instructed the jury that the immoral purpose . . .
[must] exist before the journey ends and supply the dominant
motive for the trip.”).

   We soon began considering the problem of mixed
motives. In Twitchell v. United States, we reconsidered our

     4
       We ignored Mortensen in Womble v. United States, 146 F.2d 263
(9th Cir. 1945). Dewey Womble drove from Louisville, Kentucky, to
Stockton, California with Stephen Culp and Dewel Kathleen Womble.
After arriving, Dewel Kathleen Womble began working as a prostitute.
Dewey Womble claimed “there was no evidence in that transporting
Dewel Kathleen Womble he had any intent that she should practice
prostitution.” Id. at 263. We held that intent could be “infer[red] . . . from
all the circumstances of the evidence.” Id. The Supreme Court reversed
our decision in a two-sentence opinion holding that there was “want of
substantial evidence to sustain the conviction.” Womble v. United States,
324 U.S. 830, 830 (1945) (per curiam).
                 UNITED STATES V. FLUCAS                  51

prior judgment affirming the conviction of one Harrison
Rogers. 330 F.2d 759 (9th Cir. 1964), on remand from, sub
nom., Rogers v. United States, 376 U.S. 188 (1964), vacating
in part Twitchell v. United States, 313 F.3d 425 (9th Cir.
1963). Rogers ran a motel in Everett, Washington, in which
several units were used for prostitution. A woman named
Ryan worked at the motel and occasionally oversaw the
prostitutes. When Ryan went to Portland, where she went on
a drinking spree, Rogers went and picked her up and returned
her to Everett, where she took several weeks to sober up
before returning to work at the motel. We reversed Rogers’s
conviction under the Mann Act:

        [T]here is no showing that Ryan’s trip to
        Portland was for an immoral purpose. It was
        to visit her home. The most that can be said
        of the return trip is that the dominant purpose
        was to get her sobered up and away from
        home, where she had her drinking problem.
        Nothing in the record would support a finding
        that either the or a dominant purpose of that
        trip was to have her resume immoral
        activities.

Id. at 761.

    In Bush v. United States, we found the “sole issue” was
“the intent of defendant—did he have the intent, purpose and
motive in bringing the complaining witness to California to
have her engage in immoral practices?” 267 F.2d 483, 485
(9th Cir. 1959). In Bush’s case, the issue was not a
particularly difficult one. Bush was convicted of taking a
seventeen year old from Texas to California, where she began
engaging in prostitution, jointly with Bush’s wife, who had
52               UNITED STATES V. FLUCAS

been a prostitute in Texas. Upholding the conviction, we
stated that “[i]t was not necessary that such intent be the sole
and single purpose of the transportation, if such purpose and
intent was one of the reasons for the transportation.” Id.
(citation omitted).

     We followed Bush in United States v. Fox, when we made
clear that it was “only necessary that the government prove
that [prostitution, debauchery, or other immoral purpose] was
one of the dominant purposes.” 425 F.2d 996, 999 (9th Cir.
1970) (emphasis added). We approved the instruction as “a
common and correct statement of the law.” Id. We found no
merits in the defendant’s claim that the “jury might have
misinterpreted the instruction to include situations in which
illicit activity was merely incidental to the purpose of the
interstate journey.” Id. at 1000. In a number of cases
following Fox, we hewed closely to the line that the
government must prove that unlawful sexual conduct was at
least a dominant purpose for the travel. See United States v.
Kinslow, 860 F.2d 963, 967 (9th Cir. 1988) (“In this circuit,
a federal crime under 18 U.S.C. § 2423 exists if the immoral
activity is ‘one of the dominant purposes’ of the
transportation. It is not necessary, therefore, that the immoral
activity be the only purpose of the trip.” (quoting Fox,
425 F.2d at 999)); United States v. Szymanski, 431 F.2d 946,
946 (9th Cir. 1970) (“a dominant motive”); Chargois v.
United States, 267 F.2d 410, 412 (9th Cir. 1959) (“a second
dominant and substantial purpose”). See also United States
v. Rashkovski, 301 F.3d 1133, 1137 (9th Cir. 2002); United
States v. Sangetti, 446 F.2d 552, 552 (9th Cir. 1971) (per
curiam). Cf. Hett v. United States, 353 F.2d 761, 763 (9th
Cir. 1965).
                    UNITED STATES V. FLUCAS                            53

    In United States v. Lukashov, for the first time, we
implicitly approved an instruction that a jury can convict on
proof that the interstate travel was “a dominant, significant,
or motivating purpose.” 694 F.3d 1107, 1118 (9th Cir. 2012)
(emphasis added). Lukashov was a long-distance hauler and,
on the suggestion of his wife, took his eight-year old
stepdaughter with him across the country, sexually abusing
her along the way. On appeal, Lukashov did not challenge
the jury instructions.5 Instead, he argued that the evidence
was insufficient to convict him under 18 U.S.C. § 2241(c)
because the purpose of the trip was to deliver goods to the
East Coast and return to Oregon. Id. at 1118–19. We pointed
out that Lukashov’s claim “ignores the human ability and
propensity to act in light of multiple motives and purposes.”
Id. at 1118. We found the evidence sufficient that “a jury

    5
      Before the district court, Lukashov requested an instruction that the
government must prove beyond a reasonable doubt that “one of the
dominant purposes of defendant’s interstate travel . . . was to engage in a
sexual act [with his stepdaughter].” Proposed Jury Instructions by
Alexander Lukashov, Jr, United States v. Lukashov, No. 3:14-cv-00502-
BR (D. Or. filed June 21, 2010), ECF No. 87. Instead, the district court
instructed the jury as follows:

         A person may have different purposes or motives for
         travel and each may prompt in varying degrees the act
         of making the journey. For purposes of the First
         Element,, the government must prove beyond a
         reasonable doubt that a dominant, significant, or
         motivating purpose of Defendants across a state line
         was to engage in a sexual act with [his stepdaughter].

Final Jury Instructions as to Alexander Lukashov, Jr, United States v.
Lukashov, No. 3:14-cv-00502-BR (D. Or. filed July 27, 2010), ECF
No. 139. That jury instruction is, nearly word-for-word, the instruction
approved by the Third Circuit in Hayward and adopted in Modern Federal
Jury Instructions.
54                UNITED STATES V. FLUCAS

could rationally infer that Lukashov crossed the
Montana–North Dakota and subsequent state lines with ‘a
dominant, significant, or motivating purpose’ of committing
additional sexual acts.” Id. at 1119 (quoting the district court
instruction). See also id. (“That Lukashov also had a
commercial purpose for crossing state lines does not negate
the inference that he had a significant or motiving purpose to
continue abusing [his stepdaughter] . . . .”). In passing, we
remarked that the district court “correctly instructed the jury,”
but we did not recognize the gloss the district court had added
to our prior cases by including the phrase “motivating
purpose.” Id. at 1119.

     Our subtle change in Lukashov reappeared in United
States v. Lindsay, 931 F.3d 852 (9th Cir. 2019). Lindsay was
convicted under 18 U.S.C. § 2423(b) of traveling to the
Philippines, where he had sex with a thirteen-year old girl and
paid her family money. The district court in his case gave the
jury effectively the same instruction found in Modern Federal
Jury Instructions and that we nominally approved in
Lukashov: “The government must prove that a dominant,
significant, or motivating purpose of [Lindsay’s] travel in
foreign commerce was to engage in illicit sexual conduct.”
Id. at 858. Lindsay objected to the jury instruction on appeal,
arguing that the statute required “but-for causation.” Because
Lindsay failed to object in the trial court, we reviewed for
plain error.

    “Plain error is error that is ‘clear’ or ‘obvious.’ Id. at 864
(emphasis added) (quoting Johnson v. United States 520 U.S.
461, 467 (1997)). Put another way, “plain error, as we
understand that term, is error that is so clear-cut, so obvious,
a competent district judge should be able to avoid it without
benefit of objection.” United States v. Turman, 122 F.3d
                   UNITED STATES V. FLUCAS                          55

1167 (9th Cir. 1997), see United States v. Frady, 456 U.S.
152, 163 (1982) (error is plain only if trial judge is “derelict
in countenancing it”). Thus, a court may determine that there
was no error or that there was error, but it was not clear or
obvious under current law.6 See, e.g., United States v.
Ferreyro, No. 19-50325, 2021 WL 5414854, at *1 (9th Cir.
2021) (“But, even assuming error, Ferreyro cites no authority
to support that such error was obvious.”); United States v.
Meza-Casillas, 15 F. App’x 408, 409 (9th Cir. 2001)
(“Assuming without deciding that either or both arguments
would have been well taken, the error, if any, was not ‘plain.’
A ‘plain’ error means an error that ‘is so clear-cut, so obvious
a competent district court judge should be able to avoid it
without benefit of [any] objection.’ The error here, if any,
does not meet that standard.). Contrary to the majority’s
characterization of Lindsay, we did not hold that the
instruction was not erroneous. See Maj. Op. at 20. Rather,
citing Lukashov, we held that it was “not obviously wrong”
and “the district court did not plainly err by instructing the
jury that Lindsay traveled in foreign commerce for the
purpose of engaging in illicit sexual activity if that purpose
was dominant, significant, or motivating.” Id. at 19
(emphasis added). Put simply, the district court’s instruction
in Lindsay may have been erroneous, but not clearly or
obviously so.

    We are not on plain error review here. If we were, I
would not only be compelled to follow Lindsay, but I would
willingly follow it. Given the confusion throughout the
federal courts, the district court’s instruction here was not

     6
       A court may also determine that an error was obvious but did not
affect substantial rights or prejudice the defendant.
56                   UNITED STATES V. FLUCAS

obviously erroneous.7 But Flucas objected repeatedly to the
instruction and made clear that he believed that the district
court had reduced the government’s burden. Given the
government’s change in requested instruction after the first
jury hung, Flucas had every reason to object.

    Our decisions, like those of our sister circuits, are
inconsistent. Our decision in Fox stated one standard—a
standard we followed in many other cases. Lukashov and
Lindsay indirectly approved a different instruction, without
acknowledging the change in the instruction. Although those
cases are more recent, neither compels our hand in this case.
Lukashov was a sufficiency-of-the-evidence case in which the
defendant apparently conceded the correctness of the
instruction. Although we pronounced the instruction correct
in passing, we did not consider the point raised by Flucas
here. So our discussion of the correctness is dicta, at best.
Lindsay was on plain error review.

    The troubling history of the jury instructions in Mann Act
cases should give us pause and force us to ask: Is there a
difference between “a dominant purpose,” “a significant
purpose,” and “a motivating purpose”? If there is not, then
why have we experimented with so many formulations? I
take up these questions in the next section.

     7
       The majority takes this long-running confusion as a sign of the
correctness of the instruction. Maj. Op. at 20 (“our holding . . . is
bolstered by a long line of consistent and uniform cases from our sister
circuits.”); see also id. at 33–34 & n.10. That is, the instruction is correct
because it is consistent with similar instructions endorsed by many courts
over a period of decades. But consistency and accuracy are distinct.
Courts can be consistently wrong.
                 UNITED STATES V. FLUCAS                    57

                               II

    People are complex. We are pulled by competing
interests, representing people, events, and circumstances.
Some choices in life are mutually exclusive. We can attend
the symphony or go the movies. We can’t do both at the
same time. But many times, we can accommodate more than
one interest—we pick up the dry cleaning on our way home
from grocery shopping. We go to the university library to
begin research on a term paper, but that is also where our
friends are hanging out tonight, and it is quieter than staying
in the dorm. And we are capable of holding in our minds
multiple reasons for our choices. But not every reason is as
important as every other reason. Figuring out what moves us
is one of the joys and terrors of life. It is also core to
determining mens rea.

                              A

    “Dominant,” “significant,” and “motivating” are three
ways of expressing different degrees of influence on a
person’s decision-making. To my mind, they represent a
hierarchy of explanations for our decisions. “Dominant”
means “[e]xercising chief authority or rule: ruling, governing,
[or] commanding; most influential” and “[o]ccupying a
commanding position.” Dominant, Oxford English Dictionary
(2d ed. 1989) (emphasis added). This represents the most
demanding standard. A dominant purpose would occupy a
commanding position in an individual’s decision-making
process. That is, it would be at the forefront of the
individual’s mind when making the decision. “Significant”
means “[s]ufficiently great or important to be worthy of
attention; noteworthy; consequential, influential” or
“noticeable, substantial, considerable, large.” Significant,
58               UNITED STATES V. FLUCAS

Oxford English Dictionary (2d ed. 1989). This is, admittedly,
not an obvious or large step down from dominant. But it does
capture an important idea—a purpose need not be the
dominant purpose, but it must bear some significance in our
decision. In other words, it should be a dominant purpose,
even if it is not the dominant purpose.

     By contrast, “motivate” means “[t]o provide or serve as
a rationale for (some action, etc.); to justify.” Motivate,
Oxford English Dictionary (2d ed. 1989). This conveys little
sense of comparative weight or importance in the decision-
making process. A factor can play a small role in a person’s
decision-making and still motivate them. If we are going to
the grocery store because we have no food in the house for
dinner, stopping at the dry cleaners might be useful if it is on
the way; it supplies an additional motive for the trip, even if
it is not so important as to justify a separate trip. Picking up
the dry cleaning provides additional value to the trip to the
store. That may help motivate us to go (or to go now, before
the dry cleaners closes) without being the dominant or even
a significant reason for leaving the house. If we are not in
hurry to collect the dry cleaning, it may be entirely incidental
to our reasons for going out. Even our grocery shopping has
its own set of priorities. We need milk, bread, and eggs, but
we also pick up a frozen pizza and a Midnight Milky Way.
Does each of these items motivate us? Are they of equal of
value? Is one or more of the items the dominant reason? A
significant reason?

    I don’t think that “motivating” can bear the same weight
as either “dominant” or “significant.” It may carry such
weight, but it does not necessarily carry the same weight.
Here is how we test that.
                     UNITED STATES V. FLUCAS                               59

    Following Mortensen, federal courts added to their
instructions the caveat that the government did not have to
prove that crossing state lines for illicit purposes was “the
dominant purpose” for the trip; it was sufficient if it was “a
dominant purpose.” Similarly, it doesn’t do violence to the
rule to say that the government doesn’t have to prove that
interstate travel for illicit purposes was not “the significant
purpose,” but only “a significant purpose.” As a matter of
ordinary conversation, it is also easy to see how we
might—in our effort to provide more word clues for the
jury—think that the government also does not have to prove
that interstate travel was “the motivating purpose,” but only
“a motivating purpose.” But here is where those formulations
break down. Once the jury is told that travel must be “a
motivating purpose,” it is a short step for the jury to think that
the government satisfies its burden if it has proven that
interstate travel for illicit purposes was any motivating
purpose, no matter how insignificant.8 Indeed, “dominant”
and “significant” are frequently used as modifiers before
some variant of “motivating” in order to emphasize that not
any motivation will satisfy the criteria under examination.
See, e.g., American Legion v. American Humanist Ass’n,
139 S. Ct. 2067, 2085 (2019) (“This is not to say that the

    8
      Instructing the jury that traveling across state lines for illicit sexual
activity may not be “merely incidental” to the trip is not sufficient to
overcome this error. “Incidental” means “[o]ccurring or liable to occur in
fortuitous or subordinate conjunction with something else of which it
forms no essential part; casual.” Incidental, Oxford English Dictionary (2d
ed. 1989). Thus, to say that illicit sexual activity may not be “merely
incidental” tells the jury that it must have played, at a minimum, some
minor role beyond fortuity in the decision to make the trip. That
represents a significant departure from the “dominant purpose” test
expounded by the Supreme Court in Mortensen and that we adopted in
Fox.
60               UNITED STATES V. FLUCAS

cross’s association with the war was the sole or dominant
motivation for the inclusion of the symbol in every World
War I memorial that features it.”); Pena-Rodriguez v.
Colorado, 137 S. Ct. 855, 867 (2017) (“The Court must
decide whether the Constitution requires an exception to the
no-impeachment rule when a juror's statements indicate that
racial animus was a significant motivating factor in his or her
finding of guilt.”); Palmer v. Thompson, 403 U.S. 217, 225
(1971) (“It is difficult or impossible for any court to
determine the ‘sole’ or ‘dominant’ motivation behind the
choices of a group of legislators.”).

    The hierarchy of terms I have proposed here is reflected
in United States v. Generes, 405 U.S. 93 (1972). It is a tax
case, and the particulars are not important to us. But the case
“turn[ed] on the proper measure of the required proximate
relation” between a bad debt and the taxpayer’s business. Id.
at 96. The court had to determine whether “this necessitate[s]
a ‘dominant’ business motivation on the part of the taxpayer,
or is a ‘significant’ motivation sufficient?” Id. at 96. In
posing the question, the Court implicitly recognizes that there
is a distinction between these two terms. Ultimately, the
Court held that a proof of a significant motivation is different
from proof of a dominant motivation. “We conclude that . . .
the proper measure is that of dominant motivation, and that
only significant motivation is not sufficient.” Id. at 103. By
the Supreme Court’s reasoning, any “motivation” is certainly
an even lower bar than either qualifier that the Court
considered.

   Similarly, in United States v. Miller, a Mann Act case
from the Second Circuit, Miller argued that the Act requires
proof that criminal sexual activity was “the dominant
purpose.” 148 F.3d 207, 211 (2d Cir. 1998). The court
                UNITED STATES V. FLUCAS                  61

rejected the argument. In the process, the Second Circuit
used “motivation” and “purpose” interchangeably and
explained why one could have more than one dominant
purpose for an act:

       [I]n everyday speech we can and do describe
       groups as “dominant.” For example, it makes
       perfect sense to discuss the “dominant
       companies” in an industry or the “dominant
       teams” in a league, and all we mean by
       describing these companies or teams as
       “dominant” is that they are relatively more
       successful or influential than others.
       Likewise, in the context of multiple purposes,
       “dominant” simply means that these
       motivations predominate over other, less
       powerful motivations for conduct.

Id. at 212. If “a motivating purpose” will satisfy the Mann
Act, we will have no reason to ask the jury whether “these
motivations predominate over other less powerful
motivations for conduct”—because any motivating purpose
will do.

                             B

    This analysis is confirmed in the 2018 amendments to the
current version of the Mann Act. The 2018 amendment to
Section 2423(b) makes clear what the dictionary definitions
suggest—“motivating” is a lesser standard than “dominant”
or “significant.” Section 2423, a derivative of Section 4 of
the Mann Act, provides harsh penalties for transporting
minors to engage in illicit sexual activity. Compare
18 U.S.C. § 2421(a) (providing for sentences of “not more
62                  UNITED STATES V. FLUCAS

than 10 years”) with id. § 2423(a) (providing for sentence of
“not less than 10 years or for life”); id. 2423(b) (providing for
sentence of “not more than 30 years).9 Prior to 2018,
§ 2423(b) made it a crime for “[a] person [to] travel[] in
interstate commerce or travel[] into the United States . . . for
the purpose of engaging in any illicit sexual conduct.” In
2018, Congress amended § 2423(b) to make one small
change. The current version of § 2423(b) reads, “A person
who travels in interstate commerce or travels into the United
States . . . with a motivating purpose of engaging in any illicit
sexual conduct with another person . . . .” 18 U.S.C. § 2423
(emphasis added). “With a motivating purpose,” replaced
“for the purpose of” in the prior iteration of the statute.
Critically, Congress did not amend any other sections of the
Mann Act, including the two provisions under which Flucas
was convicted—§§ 2421(a), 2423(a). Prior to the 2018
amendment, most federal courts had treated § 2423(b) similar
to §§ 2421(a) and 2423(a) and had used “dominant” and
“significant” as the qualifiers for “purpose.” See Schneider,
801 F.3d at 194; McGuire, 627 F.3d at 624–25; Vang,
128 F.3d at 1072–73; but see United States v. Garcia-Lopez,
234 F.3d 217, 219–20 (5th Cir. 2000) (holding it was not
error for the district court to refuse to give “a significant or
dominant purpose” instruction and instead instruct that it was
“enough if one of the defendant’s motives in traveling in
foreign commerce was to engage in a sexual act with a
minor”).

     9
      Section 2423 applies to crimes involving minors. Section 2423(a),
which has language nearly identical to 2421(a), punishes persons who
transport minors “with intent that the individual engage in engage in
prostitution, or in any sexual activity for which any person can be charged
with a criminal offense.” Section 2423(b) punishes person who travel to
engage in illicit sexual conduct. Section 2423(b) does not require that the
defendant have transported anyone.
                      UNITED STATES V. FLUCAS                               63

    Why did Congress tinker with the language? The statute
was amended as part of the Abolish Human Trafficking Act
of 2017 to make it easier to convict sex tourists. While
§§ 2421(a) and 2423(a) punish those who transport persons
for illicit sex, § 2423(b) punishes those who travel for illicit
sex. As a legislative summary explained: “In order to help
curb foreign offenders and internal [sic] human trafficking,
the legislation clarifies that persons who travel overseas with
a motivating purpose of engaging in illicit sex tourism can be
federally prosecuted for their offense.” Cornyn, Klobuchar
Bill to Fight Human Trafficking Signed into Law, East
Texas Review (Dec. 22, 2018) (emphasis added),
https://easttexasreview.com/cornyn-klobuchar-bill-fight-hu
man-trafficking-passes-senate/. Congress’s concern with sex
tourism is understandable in context. Whereas §§ 2421(a)
and 2423(a) punish one who “knowingly transports” a victim
across state lines for a particular purpose—a deliberate act
involving at least two people—§ 2423(b) punishes mere
“travel” across a border with bad intent. It makes sense for
Congress to try to reach a sex tourist who comes to the United
States with mixed motives—to see the Empire State Building
and the Grand Canyon and also to have illicit sex. In that
situation, Congress might well try the outer boundaries of its
authority to punish any “motivating purpose” for travelers,
but be satisfied with the historic limits—a “dominant” or
“significant” purpose—when it comes to persons who
knowingly transport others for immoral purposes.10 By

     10
         Section 2423(c) has lowered the bar to prosecution even more. It
makes it illegal to travel in foreign commerce “and engage[] in any illegal
sexual conduct.” 18 U.S.C. § 2423(c). No proof of intent or motive is
required; it is a strict liability statute. United States v. Pepe, 895 F.3d 679,
688 n.4 (9th Cir. 2018) (“[Section] 2423(c) doesn’t itself require a mens
rea . . . .”). See Sex Tourism Prohibition Improvement Act of 2002, H.R.
Rep. No. 107-525, at 3 (The bill “eliminates the intent requirement”), 5
64                  UNITED STATES V. FLUCAS

making “motivating purpose” the standard in § 2423(b),
Congress lowered the government’s burden of proof for
conviction. The 2018 amendment removes any possibility
that a jury may acquit if the defendant’s purpose was not a
dominant or significant one. By not amending §§2421(a) and
2423(a) at the same time, Congress left the higher burden of
proof in place.

                                    III

    My concerns are not mere classroom hypotheticals.
When the district court added that word “motivating” to the
jury instruction, it lowered the government’s burden of proof.
At Flucas’s second trial, the jury was told that it was
sufficient if the government has proven that “the sexual
activity was a significant, dominant, or motivating purpose”
for Flucas’s move to California. We should not be surprised
that the jury thought that it could convict Flucas if the sexual
activity was “any motivating purpose” for his travel from
Oregon to California. That is a clear departure from the
Supreme Court’s decision in Mortensen.

    The district court’s decision to add “or motivating” to the
instruction plainly was a critical change from the first trial to
the second. The government didn’t request it idly, and
Flucas’s counsel promptly objected and identified the

(2002). I note that the 2002 bill did not pass, but it became the basis for
later amendments. See Sara Sun Beale, Prosecuting Sexual Exploitation
and Trafficking Abroad: Congress, the Courts, and the Constitution,
27 Duke J. Gender L. & Pol’y 25, 26–27, 27 n.12 (2020).
                    UNITED STATES V. FLUCAS                            65

problem for the district court.11 When the second jury was
told it could find Flucas guilty if “the [illegal] sexual activity
was a significant, dominant, or motivating purpose,” only one
of those needed be true to convict because the instruction was
phrased in the disjunctive. That gave the jury a choice of
standards, and we must assume that it chose the common
denominator—“motivating”—because satisfying that
standard would automatically satisfy the higher standards of
“dominant” and “significant.”12 The instruction thus
improperly lowered the bar from the required intent—a
dominant or significant purpose.

    That reduced standard could have made a difference here,
one that we cannot conclude was harmless beyond a
reasonable doubt. See McDonnell v. United States, 136 S. Ct.
2355, 2375 (2016); Chapman v. California, 386 U.S. 18, 24
(1967). The evidence in this case must have been difficult to
hear. Flucas testified at trial and he admitted to having sex

    11
       Counsel for Flucas explained his objection to the district court: “I
think significant and dominant are equal. Motivating is lower. And
incidental is even lower than that. So I think that motivating is—just
means something totally different than significant or dominant.” He
advised the court that “significant” and “dominant” had been approved in
prior cases, “but the motivating is a new—a new word put in there.”
    12
       The majority refers to my point as a “speculative assertion.” Maj.
Op. 13 n.6. I am not sure why that is significant. We never know what
the basis for a jury’s decision is. We assume that juries follow their
instructions. United States v. Mitchell, 502 F.3d 931, 990 (9th Cir. 2007).
“We cannot know what this jury did behind closed doors. The standard
the jury applied can only be gleaned from examining what the jury was
told.” Chalmers v. Mitchell, 73 F.3d 1262, 1267 (2d Cir. 1996). Flucas’s
jury was provided with a disjunctive, and one of the alternatives is
erroneous. We have to assume that the jury followed the district court’s
instruction and decided on the basis of the bad instruction.
66               UNITED STATES V. FLUCAS

with at least one of his daughters and a stepdaughter and
fathering children by them. There was also very strong
evidence that Flucas had repeatedly had sex with his
daughters and others over a long period, including his time in
Georgia, his stay in Oregon, and after his move to California.
And the government elicited from Flucas that he knew what
he had done was wrong and that he had considered fleeing the
country. But the evidence that illicit sexual conduct with his
daughters and other young women was a dominant or
significant reason Flucas moved his family from Oregon to
California was flimsy. Flucas was settled in Klamath Falls,
Oregon, where he had a job with the school district that
worked out to about $18 per hour. In addition to his salary,
he received another $10,000 to compensate him for his
mileage. Flucas had asked the Klamath school district for
more money, but the district told him there would be no bump
in salary and that it planned to reduce his mileage
compensation. In the meantime, the Stockton Unified School
District made him a better offer, one that would work out to
about $31 per hour, plus compensation for his mileage. It
would be more money for fewer hours. In addition, the
school district offered his wife a salaried position as well,
also working with hearing-impaired students.

    So why did Flucas move to California? To take a new
job, as the defense argued? Or to continue to sexually abuse
his children, as the government claimed? The choices are not
mutually exclusive, but they do require some assessment of
the relative weight of Flucas’s motives for accepting a new
teaching position and moving his family. But without
considering the relative weight of his reasons for moving, the
jury may be very tempted to punish Flucas because (1) he
crossed a state line and (2) he was a serial sexual abuser. But
traveling across a state line while a serial sex abuser is not
                 UNITED STATES V. FLUCAS                    67

sufficient for a conviction under the Mann Act. Being a serial
sexual abuser describes one’s status, not a purpose for
crossing a state line. There is a serious doubt that Flucas
crossed the Oregon-California border with his family and
moving truck as “calculated means for effectuating sexual
immorality.” Mortensen, 332 U.S. at 375.

                           ****

    One final, broader observation. The Mann Act is a
parasitic act because it depends on violations of the laws of
non-federal jurisdictions. The Act punishes “any sexual
activity for which any person can be charged with a criminal
offense.” 18 U.S.C. § 2421(a). Sex crimes are traditionally
defined by state law. That means that the interstate
transportation element is the only thing that narrows the
Mann Act; otherwise, federal law would be at least
coextensive with state law. This should concern us. “[G]iven
the structure of our federal criminal justice system, we would
expect that state laws criminalizing sexual activity with
minors would encompass a broader range of conduct than
federal laws.” United States v. McCauley, 983 F.3d 690, 696
(4th Cir. 2020). We should hesitate long before we attribute
to Congress an exercise of power to displace the states in this
traditional area of state control. See United States v. Lopez,
514 U.S. 549, 564 (1995) (warning that the “implications of
the Government’s arguments” make it “difficult to perceive
any limitation on federal power . . . in areas such as criminal
law enforcement . . . where States historically have been
sovereign.”). “When charged conduct does not fall in the
heartland of [the Mann Act’s] proscription, the risk of
prejudice becomes more palpable.” McCauley, 983 F.3d
at 698. This is not to say that Flucas’s “conduct was in any
way excusable or beyond the reach of the criminal law. It is
68                UNITED STATES V. FLUCAS

simply that it is quite possible that properly instructed the
jury would find this defendant’s conduct falls outside” of
federal criminal jurisdiction. Id.

                               IV

    I would reverse the judgment of conviction and remand
to the district court with instructions that if the government
wishes to retry Flucas, the jury must be instructed that his
continued illicit sexual conduct was one of the dominant or
significant purposes for moving his family from Oregon to
California.

     For these reasons, I respectfully dissent.