You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


PUBLISHED

UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT

THE PITTSTON COMPANY; BUFFALO
MINING COMPANY; CLINCHFIELD COAL
COMPANY; EASTERN COAL
CORPORATION; ELKAY MINING
COMPANY; JEWELL RIDGE COAL
CORPORATION; KENTLAND-ELKHORN
COAL CORPORATION; MEADOW RIVER
COAL COMPANY; PITTSTON COAL
GROUP; RANGER FUEL CORPORATION,
Plaintiffs-Appellants,

v.

UNITED STATES OF AMERICA,
Defendant & Third Party
Plaintiff-Appellee,

v.
                                     No. 98-2398

MICHAEL H. HOLLAND, Trustee of
the United Mine Workers of
America Combined Benefit Fund;
UNITED MINE WORKERS OF AMERICA
COMBINED BENEFIT PLAN; ELLIOT A.
SEGAL, Trustee of the United Mine
Workers of America Combined
Benefit Fund; WILLIAM P. HOBGOOD,
Trustee of the United Mine Workers
of America Combined Benefit
Fund; MARTY D. HUDSON, Trustee of
the United Mine Workers of
America Combined Benefit Fund;
THOMAS O. S. RAND, Trustee of the
United Mine Workers of America
Combined Benefit Fund; GAIL R.
WILENSKY, Trustee of the United
Mine Workers of America
Combined Benefit Fund; CARL E.
VAN HORN, Trustee of the United
Mine Workers of America
Combined Benefit Fund,
Third Party Defendants-
Appellees,

and

THE BITUMINOUS COAL OPERATORS'
ASSOCIATION, INCORPORATED;
INTERNATIONAL UNION, UNITED MINE
WORKERS OF AMERICA,
Parties in Interest.

Appeal from the United States District Court
for the Eastern District of Virginia, at Richmond.
James R. Spencer, District Judge.
(CA-97-294)

Argued: September 23, 1999

Decided: December 27, 1999

Before WILKINS, NIEMEYER, and TRAXLER, Circuit Judges.

_________________________________________________________________

Reversed and remanded by published opinion. Judge Wilkins wrote
the majority opinion, in which Judge Traxler joined. Judge Niemeyer
wrote a dissenting opinion.

_________________________________________________________________

COUNSEL

ARGUED: Wade Wallihan Massie, PENN, STUART &
ESKRIDGE, Abingdon, Virginia, for Appellants. Jeffrey A. Clair,

                    2
Civil Division, UNITED STATES DEPARTMENT OF JUSTICE,
Washington, D.C.; Stephen John Pollak, SHEA & GARDNER,
Washington, D.C., for Appellees. ON BRIEF: Stephen M. Hodges,
PENN, STUART & ESKRIDGE, Abingdon, Virginia; Gregory B.
Robertson, HUNTON & WILLIAMS, Richmond, Virginia; A.E. Dick
Howard, Charlottesville, Virginia, for Appellants. David W. Ogden,
Acting Assistant Attorney General, Helen F. Fahey, United States
Attorney, Douglas N. Letter, Civil Division, UNITED STATES
DEPARTMENT OF JUSTICE, Washington, D.C., for Appellee
United States. Wendy S. White, Howard R. Rubin, SHEA & GARD-
NER, Washington, D.C.; Samuel M. Brock, III, MAYS & VALEN-
TINE, L.L.P., Richmond, Virginia, for Appellees Holland, et al.

_________________________________________________________________

OPINION

WILKINS, Circuit Judge:

The Pittston Company1 (Pittston) appeals an order of the district
court that, in relevant part, dismissed under the doctrine of claim pre-
clusion Pittston's claim that the Coal Industry Retiree Health Benefit
Act of 1992 (the Coal Act), see 26 U.S.C.A.§§ 9701-22 (West Supp.
1999), violates the nondelegation and separation of powers doctrines
of the United States Constitution by improperly placing governmental
powers and federal revenues in the hands of a private entity. Pittston
also appeals an order of the district court denying its motion to amend
its complaint to add claims based on the Due Process and Takings
Clauses of the Fifth Amendment. Concluding that the district court
erred on both points, we reverse and remand for further proceedings.
_________________________________________________________________

1 This suit was instituted by The Pittston Company, Buffalo Mining
Company, Clinchfield Coal Company, Eastern Coal Corporation, Elkay
Mining Company, Jewell Ridge Coal Corporation, Kentland-Elkhorn
Coal Corporation, Meadow River Coal Company, Pittston Coal Group,
and Ranger Fuel Corporation. For ease of reference, we refer to this case
as having been prosecuted solely by The Pittston Company.

                    3
I.

A.

The issue of health care benefits for retired coal industry workers
and their dependents has a protracted history. See generally Eastern
Enters. v. Apfel, 118 S. Ct. 2131, 2137-42 (1998) (plurality opinion)
(discussing history leading to the enactment of the Coal Act); id. at
2165-66 (Breyer, J., dissenting) (same); Holland v. Big River Miner-
als Corp., 181 F.3d 597, 600-01 (4th Cir. 1999) (same); Holland v.
Keenan Trucking Co., 102 F.3d 736, 738-39 (4th Cir. 1996) (same).
Disputes concerning health care for miners date back to the time early
in this century when such care was funded with a prepayment plan
through payroll deductions and was supplied by company doctors. In
the 1930s and 1940s, the United Mine Workers of America (UMWA)
and coal industry employers sought changes in the method of provid-
ing essential services to miners, and from the late 1940s through the
early 1970s pension and medical benefits were provided by several
UMWA funds created under a series of National Bituminous Coal
Wage Agreements (NBCWAs), including a 1950 and a 1974 UMWA
Benefit Plan. The funding for these benefits was supplied in part by
a royalty on each ton of coal mined and in part by payroll deductions.
As benefits improved under UMWA plans and the number of benefi-
ciaries increased, other factors such as a decrease in the amount of
coal produced and a rapid increase in health care costs conspired to
produce financial problems for the funds. In response to these finan-
cial pressures, the 1978 NBCWA allocated to signatory employers
responsibility for the health care costs of their active and retired min-
ers. The 1974 UMWA Benefit Plan remained in place, but was
responsible for providing benefits only to "orphaned" retired miners
--those whose former employers were no longer in business.

Despite this restructuring, the benefit plans continued to suffer
financially, and by the late 1980s they were facing insolvency. Unrest
concerning this situation led to an 11-month strike beginning in 1989
by mine workers against the Pittston Coal Company, which ended
only after the Secretary of Labor intervened and negotiated a settle-
ment. Thereafter, the Secretary established the Advisory Commission
on United Mine Workers of America Retiree Health Benefits (the
"Coal Commission"), a bipartisan commission formed to assess the

                     4
financial outlook of the UMWA health benefit plans and to devise
possible strategies to guarantee the long-term viability of the plans.
The Coal Commission concluded that retired miners were entitled to
the health benefits that had been promised them and that such com-
mitments must be honored; that a statutory obligation to fund the ben-
efits should be imposed on current and former signatories to
NBCWAs; and that an improved means of funding benefits for
orphaned miners should be developed. After conducting hearings on
the Coal Commission's recommendations, Congress enacted the Coal
Act in 1992. Congress found that

          in order to secure the stability of interstate commerce, it is
          necessary to modify the current private health care benefit
          plan structure for retirees in the coal industry to identify per-
          sons most responsible for plan liabilities in order to stabilize
          plan funding and allow for the provision of health care bene-
          fits to such retirees.

26 U.S.C.A. § 9701 note.

Toward these goals, the Coal Act legislated significant changes in
health benefits for retired coal workers. Most relevant to the present
case, it consolidated the 1950 and 1974 UMWA Benefit Plans into the
United Mine Workers of America Combined Benefit Fund (the Com-
bined Fund). See id. § 9702(a)(2). Coal companies pay annual premi-
ums to the Combined Fund. See id. § 9704(a). The Fund, in turn,
provides health and death benefits to coal industry retirees who, as of
July 20, 1992, were eligible to receive and were receiving benefits
from the 1950 or 1974 UMWA Benefit Plans and to those receiving
or eligible to receive such benefits as of such date by virtue of a rela-
tionship to such a retiree. See id. § 9703.

The Coal Act provides that each retiree is assigned to a former
employer that was a signatory to a NBCWA and that remains in busi-
ness. Assignments are made in an order prescribed in the Act. A
retiree is first assigned to the operator that was a signatory to the 1978
or subsequent NBCWA and that most recently employed the retiree
in the coal industry for at least two years. See id. § 9706(a)(1). If no
such operator exists, the retiree is assigned to the operator that was
a signatory to the 1978 or subsequent NBCWA and that most recently

                     5
employed the retiree in the coal industry for any length of time. See
id. § 9706(a)(2). If no operator meets those criteria, the retiree is
assigned to the signatory operator that employed the retiree in the coal
industry for the longest period of time prior to the effective date of
the 1978 NBCWA. See id. § 9706(a)(3). These "assigned operators"
are then required to pay annual premiums to the Combined Fund for
each person assigned to them. See id. § 9704.

A retiree not assigned under § 9706 is an"unassigned beneficiary."
See id. § 9704(d). Health care payments for unassigned beneficiaries
derive from three sources, the first two being surpluses from the 1950
UMWA Pension Plan that are transferred to the Combined Fund, see
id. § 9705(a), and transfers from the Abandoned Mine Reclamation
Fund, see id. § 9705(b); 30 U.S.C.A.§ 1232(h) (West Supp. 1999).
If these sources prove insufficient to pay for the unassigned beneficia-
ries' health care, an "unassigned beneficiaries premium" is assessed
to each assigned operator based on the number of its assigned benefi-
ciaries. See 26 U.S.C.A. § 9705(a)(3); id. § 9704(a)(3).

An assigned operator's health benefit premium for assigned benefi-
ciaries for any year is the product of the "per beneficiary premium"
for that year multiplied by the number of eligible beneficiaries
assigned to that operator under 26 U.S.C.A. § 9706. See id.
§ 9704(b)(1). The per beneficiary premium for each year is calculated
by adjusting the per beneficiary premium for the initial year--1993--
for inflation. See id. § 9704(b)(2). The Coal Act as originally enacted
provided that the Secretary of Health and Human Services (the Secre-
tary) would calculate the amount of the per beneficiary premium and
assign beneficiaries to assigned operators. See 26 U.S.C.
§§ 9704(b)(2), 9706(a) (Supp. IV 1993). However, effective March
31, 1995, both of those duties were transferred to the Commissioner
of Social Security (the Commissioner). See Social Security Indepen-
dence and Program Improvements Act of 1994, Pub. L. No. 103-296,
§ 108(h)(9)(A), (B), 108 Stat. 1464, 1487-88 (1994).

B.

Pittston is a Virginia corporation whose subsidiaries and predeces-
sors have been mining coal in the eastern United States for the past
150 years. In 1997, Pittston initiated this tax refund action, see 26

                    6
U.S.C.A. § 7422 (West Supp. 1999); 28 U.S.C.A.§ 1346(a)(1) (West
1993), against the United States (the Government) seeking the return
of certain premiums Pittston had paid under the Coal Act. In Count
One, Pittston alleged that the Coal Act violated the nondelegation and
separation of powers doctrines of the United States Constitution. On
this basis, Pittston sought a refund of all payments made under 26
U.S.C.A. § 9704 for tax years 1993 through 1996. In Count Two, Pitt-
ston sought a refund of certain overpayments that it had been com-
pelled to make under the Coal Act for tax years 1993 through 1995.2

The Government moved to dismiss on several grounds, including
that the judgment in National Coal Ass'n v. Chater, No. CV94-H-
780-S, 1995 U.S. Dist. LEXIS 21125 (N.D. Ala. July 20, 1995), aff'd,
81 F.3d 1077 (11th Cir. 1996) (per curiam), barred Pittston's action
under the doctrine of claim preclusion. In National Coal, an industry
group and several coal companies, including Pittston, brought an
action challenging the method that the Secretary used to calculate the
initial per beneficiary premium--the amount of which would affect
Pittston's total Coal Act premium liability for the initial year and all
subsequent years--and requesting that the Secretary be ordered to
recompute the affected premiums in accordance with the applicable
statute. The district court held that the Secretary's methodology was
indeed incorrect and ordered the Secretary to recompute the premi-
ums using the correct methodology. See National Coal, 1995 U.S.
Dist. LEXIS 21125, at *1-2. The Eleventh Circuit affirmed. See
National Coal, 81 F.3d at 1082.

The district court granted the Government's motion to dismiss
Count One and denied the Government's motion to dismiss Count
Two in an order dated September 11, 1997. The district court held
that National Coal barred Count One because Pittston "could have ...
raised" that claim in that case, J.A. 119, but that Count Two was not
barred because Pittston "could not have raised" a claim for refund of
overpayments before obtaining a ruling that the premium had been
miscalculated, J.A. 120.
_________________________________________________________________
2 The basis for these overpayments arose from the Secretary's incorrect
calculation of the per beneficiary premium, which we will discuss later
in the opinion.

                    7
Shortly thereafter, on October 9, 1997, the Government filed a
third-party complaint against the Trustees of the Combined Fund and
the Fund itself (collectively, "the Trustees"). Because the Coal Act
requires operators to pay premiums to the Fund directly, the Govern-
ment sought indemnity for all amounts that the Government might be
ordered to pay Pittston.

Following discovery regarding Count Two, Pittston and the Gov-
ernment filed cross-motions for summary judgment. On February 3,
1998, the district court granted Pittston's motion, denied the Govern-
ment's motion, and directed the Government to refund to Pittston
$1,916,641.96 in overpayments and prejudgment interest.3 In so
doing, the court held that Coal Act premiums are taxes refundable
under 28 U.S.C.A. § 7422 and that § 7422 was not preempted by the
Employee Retirement Income Security Act (ERISA) of 1974, see 29
U.S.C.A. §§ 1001-1461 (West 1999 & Supp. 1999). The judgment
entered by the district court clerk in Pittston's favor stated that "[t]he
third-party action will now proceed." J.A. 495. Pittston subsequently
moved the court to amend its disposition of Pittston's suit to clarify
whether the judgment was final at that time. By order filed April 1,
1998, the court amended its disposition to state that "the Court's deci-
sion and order of February 3, 1998 and the judgment entered on Feb-
ruary 4, 1998 are not now final or appealable under Fed. R. Civ. P.
54(b) or Fed. R. App. P. 4 and shall not become final or appealable
until the third-party action is concluded." J.A. 505.

C.

On June 25, 1998, the United States Supreme Court held that Con-
gress acted arbitrarily in violation of the Fifth Amendment in impos-
ing retroactive liability on a signatory to NBCWAs existing prior to
those that promised lifetime health benefits to retired miners when
that signatory made no promise of lifetime benefits, did not contribute
to the problem that caused the funding shortfall for the promised life-
time benefits or to the need for such benefits, and was not put on
notice by any governmental action during the relevant time period
that it might be subjected to later liability. See Eastern Enterprises v.
_________________________________________________________________
3 The Government appealed the judgment against it, but the parties sub-
sequently settled the matter and the appeal was voluntarily dismissed.

                     8
Apfel, 118 S. Ct. 2131, 2151-53 (1998) (plurality opinion); id. at
2159-60 (Kennedy, J., concurring in the judgment and dissenting in
part); see also Holland v. Big River Minerals Corp., 181 F.3d 597,
606 (4th Cir. 1999) (setting forth the holding of the court). Four jus-
tices concluded that the Coal Act as applied constituted a taking and
one concluded that it violated substantive due process.

Relying on Eastern Enterprises, Pittston moved on August 6, 1998
for leave to amend its complaint to add claims asserting that (1) as
applied, the Coal Act constitutes a taking and violates substantive due
process, and (2) the funding provisions of the Coal Act are not sever-
able, and thus the Coal Act is invalid as to Pittston and the other con-
tributors to the Combined Fund. The latter claim is based on Pittston's
contention that Eastern Enterprises eliminated an entire class of con-
tributors to the Combined Fund. Pittston maintains that the elimina-
tion of this source of funding materially increases the burden on other
contributors to the Combined Fund and that Congress would not have
passed the Coal Act without funding from the eliminated class. See
Connolly v. Union Sewer Pipe Co., 184 U.S. 540, 565 (1902)
(explaining that if an unconstitutional section of a statute "is of such
import that the other sections without it would cause results not con-
templated or desired by the legislature, then the entire statute must be
held inoperative"), overruled on other grounds by Tigner v. Texas,
310 U.S. 141, 147 (1940). Although neither the United States nor the
Trustees opposed the motion to amend, the district court denied the
motion on September 9, 1998, stating that "[t]he Court has already
issued judgment on the Complaint, and to allow Pittston to amend the
Complaint now would create undue prejudice on the opposing party."
J.A. 732. On the same day, the court also granted summary judgment
to the Government on its third-party claim for indemnity from the
Trustees.

II.

Before reaching the merits of Pittston's appeal, we must first
address two arguments made by the Government that Pittston may not
recover wrongfully assessed and calculated Coal Act premiums in a
tax refund action. First, the Government contends that Coal Act pre-
miums are not taxes.4 Second, the Government alternatively argues
_________________________________________________________________
4 The Government also contends that Pittston should be judicially
estopped from arguing that Coal Act premiums are taxes because Pittston

                    9
that even if the amount of the Coal Act premiums otherwise would
be recoverable in a tax refund action, the Coal Act bars remedies
against the Government for wrongly assessed and collected premi-
ums. We address these arguments in turn.5

A.

Absent waiver, sovereign immunity shields the United States from
suit. See FDIC v. Meyer, 510 U.S. 471, 475 (1994). Congress, how-
ever, has waived sovereign immunity from suits "for the recovery of
any internal-revenue tax alleged to have been erroneously or illegally
assessed or collected." 28 U.S.C.A. § 1346(a)(1). The question of
whether Coal Act premiums are taxes such that the Government
waived sovereign immunity under § 1346(a)(1) is a jurisdictional one
subject to de novo review. See Global Mail Ltd. v. United States
Postal Serv., 142 F.3d 208, 210 (4th Cir. 1998).

Although the Government contends that the Coal Act premiums
_________________________________________________________________
espoused the opposite view in National Coal. Pittston vehemently argues
that it took no such position in National Coal . Even assuming that Pitt-
ston did take that position, however, judicial estoppel would not bar Pitt-
ston from advancing the contrary view here. Judicial estoppel applies
only to the making of inconsistent statements of fact, and therefore is of
no relevance to Pittston's legal contention that the Coal Act premiums
are taxes. See Folio v. City of Clarksburg, 134 F.3d 1211, 1217-18 (4th
Cir. 1998) (holding that question of whether an assessment is a fee or a
tax is a legal one to which the doctrine of judicial estoppel does not
apply).

5 The Trustees, as third-party defendants, join in the Government's
arguments that Pittston cannot recover wrongly assessed or collected
Coal Act premiums in a tax refund action against the Government. They
also join the Government's position that the district court correctly dis-
missed Count One on res judicata grounds. See Fed. R. Civ. P. 14(a)
(stating that a "third-party defendant may assert against the plaintiff any
defenses which the third-party plaintiff has to the plaintiff's claim"); cf.
F & D Property Co. v. Alkire, 385 F.2d 97, 100 (10th Cir. 1967)
(explaining that "[q]uite clearly a third party defendant may resist plain-
tiff's motion for summary judgment to the same extent as the defen-
dant").

                     10
Pittston challenges are not taxes, Fourth Circuit precedent establishes
that they are. See UMWA 1992 Benefit Plan v. Leckie Smokeless Coal
Co. (In re Leckie Smokeless Coal Co.), 99 F.3d 573, 583 (4th Cir.
1996) [hereinafter Leckie]; see also Adventure Resources, Inc. v.
Holland, 137 F.3d 786, 794 (4th Cir.), cert. denied, 119 S. Ct. 404
(1998); Carbon Fuel Co. v. USX Corp., 100 F.3d 1124, 1133 (4th Cir.
1996). In Leckie, in which two appeals were consolidated, bankrupt
coal operators sought to sell their assets free and clear of their liabili-
ties under the Coal Act. See Leckie, 99 F.3d at 577-79. In each case,
a district court held that the assets could pass free and clear of the
Coal Act liabilities. See id. at 578-79.

In the consolidated appeal, a panel of this court considered whether
the district courts lacked subject matter jurisdiction to determine the
successor liability question because the Anti-Injunction Act prohibits
actions brought "for the purpose of restraining the assessment or col-
lection of any tax," 26 U.S.C.A. § 7421(a) (West Supp. 1999). See
Leckie, 99 F.3d at 582-85. Simultaneously, we considered whether the
Declaratory Judgment Act prohibited the issuance of declaratory
relief regarding the successor liability question because the Declara-
tory Judgment Act generally prohibits a district court from granting
relief "with respect to Federal taxes," 28 U.S.C.A. § 2201 (West 1994).6
See Leckie, 99 F.3d at 582-85. In addressing these questions, we first
had to "determine whether Coal Act premiums are taxes." Id. at 583.
To do so, a four-factor test was applied defining a tax as "(a) [a]n
involuntary pecuniary burden, regardless of name, laid upon individu-
als or property; (b) [i]mposed by or under authority of the legislature;
(c) [f]or public purposes, including the purposes of defraying
expenses of government or undertakings authorized by it; (d) [u]nder
the police or taxing power of the state." Id. (internal quotation marks
omitted). After considering these factors, we held that Coal Act pre-
miums are taxes. See id. Having done so, we next considered whether
the Anti-Injunction and Declaratory Judgment Acts applied under the
facts presented. Because the coal operators had no alternative legal
way of resolving the issue of successor liability, we held that the two
statutes did not preclude the district courts from reaching the merits
of the motions. See id. at 584.
_________________________________________________________________
6 We analyzed these two issues simultaneously because of the coexten-
sive nature of the two statutes. See id. at 584.

                     11
The Government makes two arguments that Leckie is not control-
ling on the issue of whether Coal Act premiums are taxes. First, it
claims that the term "tax" has "different meanings in different con-
texts" and that the definition employed by this court in determining
whether the Anti-Injunction and Declaratory Judgment Acts applied
should be different from that utilized to determine whether the premi-
ums are taxes for purposes of the refund statute. Brief for the United
States as Appellee/Cross-Appellant at 19. We disagree. The very pur-
pose of the two statutes discussed in Leckie is "to allow the Federal
Government to assess and collect allegedly due taxes without judicial
interference and to compel taxpayers to raise their objections to col-
lected taxes in suits for refunds." Leckie , 99 F.3d at 584 (citing
Enochs v. Williams Packing Co., 370 U.S. 1, 7 (1962); Flora v.
United States, 362 U.S. 145, 164 & n.29 (1960)). Accordingly, a deci-
sion that a premium is a tax for the purposes of the Anti-Injunction
and Declaratory Judgment Acts necessarily is a decision that an
objection to that assessment must be litigated in a tax refund action.7

The Government also contends that Leckie is not controlling
because our conclusion in that case that Coal Act premiums are taxes
is merely dictum. Again, we disagree. Dictum is"a statement in a
judicial opinion that could have been deleted without seriously
impairing the analytical foundations of the holding--that, being
peripheral, may not have received the full and careful consideration
of the court that uttered it." United States v. Crawley, 837 F.2d 291,
292 (7th Cir. 1988) (internal quotation marks omitted); see Hormel
Foods Corp. v. Jim Henson Prods., 73 F.3d 497, 508 (2d Cir. 1996);
see also Gillespie v. United States Steel Corp., 321 F.2d 518, 530 (6th
Cir. 1963) (concluding that statement was not dictum when "the mat-
ter was before the court ...; was argued before the court; and was
passed upon by the court"), aff'd, 379 U.S. 148 (1964).

In Leckie, the decision that Coal Act premiums are taxes was
clearly integral to the analytical foundations of our holding. The
_________________________________________________________________
7 The dissent interprets § 1346(a)(1) to waive sovereign immunity only
for actions for recovery of taxes that were paid to the Government and
not actions for recovery of taxes that were required by the Government
to be paid to a third party. However, there simply is no support for that
position in the language of the statute.

                    12
assertions that the Anti-Injunction Act deprived the district court of
subject matter jurisdiction and that the Declaratory Judgment Act pro-
hibited issuance of declaratory relief presented the court with two
questions: whether Coal Act premiums are taxes, and if so, whether
any alternative legal means existed to challenge the imposition of lia-
bility for the premiums on the purchasers of the debtors' assets. Thus,
our determination that the premiums were taxes was not "peripheral"
in any sense, and accordingly was not dictum.

B.

Assuming arguendo that Coal Act premiums otherwise would be
collectible in a tax refund action, the Government contends that the
Coal Act bars remedies against the Government for wrongly assessed
and collected premiums and requires that any action for the return of
such premiums be brought against the Combined Fund. In support of
this position, the Government argues that several provisions of the
Coal Act suggest that an operator may not bring a tax refund suit
against the Government for wrongfully assessed or collected Coal Act
premiums. In particular, the Government notes that the Coal Act pro-
vides for a procedure by which the Combined Fund can refund over-
payments when a retiree has been incorrectly assigned to an operator,
see 26 U.S.C.A. § 9706(f)(3)(A); that Congress provided that the
Combined Fund shall be treated as a multiemployer plan subject to
ERISA, see id. § 9702(a)(3)(C); and that ERISA establishes a remedy
through which employers may recover erroneous payments from a
benefit plan, see 29 U.S.C.A. § 1103(c)(2)(A)(ii) (West 1999). The
Government contends that the enactment of such detailed provisions
is ordinarily presumed to afford the exclusive remedy intended by
Congress. See United States v. Fausto, 484 U.S. 439, 448-49 (1988).
We are not persuaded by this argument.

When there are two federal statutes on "the same subject, the rule
is to give effect to both if possible." United States v. Borden Co., 308
U.S. 188, 198 (1939). While the Government is certainly correct that
Pittston has available to it remedies against the Combined Fund under
the Coal Act and ERISA, the Government has pointed us to nothing
in either act to indicate that those remedies are exclusive of all others
available under federal law, including a tax refund from the Govern-
ment. Indeed, we note that ERISA, while containing a very broad pre-

                     13
emption provision regarding state law, see 29 U.S.C.A. § 1144(a)
(West 1999), specifically states that "[n]othing in this subchapter shall
be construed to alter, amend, modify, invalidate, impair or supersede
any law of the United States." 29 U.S.C.A. § 1144(d) (West 1999).

For these reasons, we hold that a tax refund action is an appropriate
vehicle for Pittston to use to seek recovery of the challenged Coal Act
premiums. We now turn to Pittston's arguments on appeal.

III.

Pittston first contends that the district court erred in ruling that
claim preclusion barred its nondelegation and separation of powers
claims. The Government maintains that Pittston, having sought judi-
cial review of the Secretary's calculation of the initial per beneficiary
premium in National Coal, is forever barred from challenging the
constitutionality of the Coal Act. We agree with Pittston. See First
Nat'l Bank v. Russell (In re Russell), 76 F.3d 242, 244 (9th Cir. 1996)
(explaining that decision regarding whether a claim is barred by claim
preclusion is reviewed de novo).

Under the doctrine of claim preclusion, a prior judgment bars the
relitigation of claims that were raised or could have been raised in the
prior litigation.8 See First Union Commercial Corp. v. Nelson, Mul-
lins, Riley & Scarborough (In re Varat Enters.), 81 F.3d 1310, 1315
(4th Cir. 1996). However, the doctrine does not apply to all claims
that were raised or could have been raised in the prior litigation;
rather, it bars such claims only when three elements are satisfied:

           1) the prior judgment was final and on the merits, and ren-
           dered by a court of competent jurisdiction in accordance
           with the requirements of due process; 2) the parties are iden-
           tical, or in privity, in the two actions; and, 3) the claims in
           the second matter are based upon the same cause of action
           involved in the earlier proceeding.
_________________________________________________________________
8 Pittston contends that it could not have brought its constitutional
claims in the prior litigation. However, because we conclude that the
constitutional claims are not based upon the same cause of action as the
claim in National Coal, we need not reach this issue.

                     14
Id. Here, the first two elements are satisfied, and only the third
element--identity of causes of action--is in dispute. In accordance
with the modern trend, we have held that the appropriate inquiry to
determine whether causes of action are identical for claim preclusion
purposes is whether the claim presented in the new litigation "arises
out of the same transaction or series of transactions as the claim
resolved by the prior judgment." Harnett v. Billman, 800 F.2d 1308,
1313 (4th Cir. 1986); see Restatement (Second) of Judgments § 24
(1982).

No simple test exists to determine whether causes of action are
identical for claim preclusion purposes, and each case must be deter-
mined separately within the conceptual framework of the doctrine.
See Aliff v. Joy Mfg. Co., 914 F.2d 39, 43 (4th Cir. 1990). Generally,
the court must balance the interests of the defendant and of the courts
in bringing litigation to a close against the interest of the plaintiff in
not being denied the right to prosecute a valid claim. See Restatement
(Second) of Judgments § 24 cmt. b. The expression "transaction" in
the claim preclusion context "connotes a natural grouping or common
nucleus of operative facts." Id.; see In re Varat Enters., 81 F.3d at
1316. Among the factors to be considered in deciding whether the
facts of the current and prior claims "are so woven together" that they
constitute a single claim "are their relatedness in time, space, origin,
or motivation, and whether, taken together, they form a convenient
unit for trial purposes." Restatement (Second) of Judgments § 24 cmt.
b.; see Davenport v. North Carolina Dep't of Transp., 3 F.3d 89, 97
n.8 (4th Cir. 1993).

The transactions giving rise to Pittston's respective claims are not
difficult to identify. The constitutional claims asserted in the present
case arise from the 1993 through 1996 assessments, while the claim
in National Coal arose from the Secretary's calculation of the initial
per beneficiary premium. Both the National Coal claim and the con-
stitutional claims present strictly legal issues, and the Secretary's cal-
culation of the initial per beneficiary premium, while a necessary
antecedent of the imposition of the 1993 through 1996 assessments,
is clearly distinct in time, space, and origin from the assessments Pitt-
ston is now challenging. Cf. Commissioner v. Sunnen, 333 U.S. 591,
598 (1948) (explaining that in the context of income tax liability, each
tax year gives rise to a new assessment and a separate cause of

                     15
action). Further, there is no particular reason why the constitutional
claims would have combined with the calculation claim to form a
convenient trial unit, nor do we see any policy consideration that
would justify denying Pittston an opportunity to argue the merits of
its constitutional challenges to the premiums assessed against it. For
these reasons, we conclude that the constitutional claims that Pittston
now asserts are not based on the same cause of action as the claim
in National Coal, and therefore that the district court erred in barring
them. See 46 Am. Jur. 2d Judgments§ 569 (1994) (stating that when
the constitutionality of a statute is merely assumed in an earlier
action, the resulting judgment is not res judicata on the constitutional-
ity issue in a subsequent suit between the same parties on a different
cause of action).

IV.

Pittston also contends that the district court erred in denying its
motion for leave to amend its complaint after the Supreme Court
issued its decision in Eastern Enterprises. We agree.

The applicable law regarding appellate review of the denial of a
motion for leave to amend is set out in Foman v. Davis, 371 U.S. 178
(1962):

           Rule 15(a) declares that leave to amend "shall be freely
          given when justice so requires"; this mandate is to be
          heeded. If the underlying facts or circumstances relied upon
          by a plaintiff may be a proper subject of relief, he ought to
          be afforded an opportunity to test his claim on the merits.
          In the absence of any apparent or declared reason--such as
          undue delay, bad faith or dilatory motive on the part of the
          movant, repeated failure to cure deficiencies by amendments
          previously allowed, undue prejudice to the opposing party
          by virtue of allowance of the amendment, futility of amend-
          ment, etc.--the leave sought should, as the rules require, be
          "freely given." Of course, the grant or denial of an opportu-
          nity to amend is within the discretion of the District Court,
          but outright refusal to grant the leave without any justifying
          reason appearing for the denial is not an exercise of discre-

                     16
         tion; it is merely abuse of that discretion and inconsistent
         with the spirit of the Federal Rules.

Id. at 182 (citation omitted). As Foman makes clear, a court may not
exercise its discretion in a way that undermines the basic policy of
Rule 15. See Davis v. Piper Aircraft Corp., 615 F.2d 606, 613 (4th
Cir. 1980).

Here, the severability claim that Pittston sought to add could not
have been advanced prior to the issuance of Eastern Enterprises, as
that claim is based on the assertion that Eastern Enterprises elimi-
nated a whole class of contributors to the Combined Fund. Accord-
ingly, we hold that the policy favoring liberal amendment required the
district court to allow the amendment and that the district court
abused its discretion in refusing Pittston's request.

The takings and due process claims present a more difficult ques-
tion. Pittston's delay in asserting those claims was unwarranted.9
However, recognition of that fact does not end our inquiry. It is well
established in this circuit that "[d]elay alone, without prejudice, does
not support the denial of a motion for leave to amend." Deasy v. Hill,
_________________________________________________________________
9 That the delay in bringing the takings and due process claims was
unwarranted was established in Holland v. Big River Minerals Corp.,
181 F.3d 597 (4th Cir. 1999). There, after Eastern Enterprises was
decided, two coal companies sought to raise takings and due process
challenges to the Coal Act for the first time on a motion pursuant to Fed-
eral Rule of Civil Procedure 59(e). See Holland , 181 F.3d at 600. The
companies claimed an exception to the general rule that claims raised for
the first time by a Rule 59(e) motion are waived. See id. at 605. That
exception exists "when there has been an intervening change in the law
recognizing an issue that was not previously available." Id. Satisfying
that standard requires a demonstration that "there was strong precedent
prior to the change such that the failure to raise the issue was not unrea-
sonable and the opposing party was not prejudiced by the failure to raise
the issue sooner." Id. at 605-06 (internal quotation marks & citation
omitted). We held that no strong precedent prevented the companies
from raising the sort of takings and due process claims addressed in
Eastern Enterprises prior to the issuance of that decision, and therefore
that the failure to raise these claims prior to Eastern Enterprises was
unreasonable. See id. at 606-07.

                    17
833 F.2d 38, 41 (4th Cir. 1987); see Sweetheart Plastics, Inc. v.
Detroit Forming, Inc., 743 F.2d 1039, 1044 (4th Cir. 1984) (stating
that the fact that a motion for amendment was made the day of trial
is not sufficient reason for denial absent prejudice to the nonmoving
party); Davis, 615 F.2d at 613 (stating that"[d]elay alone ..., without
any specifically resulting prejudice, or any obvious design by dilatori-
ness to harass the opponent, should not suffice as reason for denial"
of a motion to amend). Here, Pittston's motion to amend was unop-
posed and the Government has not identified any way in which it was
prejudiced by Pittston's failure to amend its complaint sooner than it
did.

The district court, in its order denying the motion for leave to
amend, did not indicate that it found any bad faith on Pittston's part
and did not identify how it believed the Government might be preju-
diced by the late amendment. Rather, the court stated only that it had
"already issued judgment on the Complaint, and to allow Pittston to
amend the Complaint now would create undue prejudice on the
opposing party." J.A. 732. We read that explanation to mean that the
district court considered that the lateness and delay constituted preju-
dice per se. Because that analysis is contrary to the law of this circuit,
see Deasy, 833 F.2d at 41; Sweetheart Plastics, 743 F.2d at 1044;
Davis, 615 F.2d at 613, we must conclude that the district court
abused its discretion in denying Pittston leave to amend its complaint
to add the takings and due process claims. See James v. Jacobson, 6
F.3d 233, 239 (4th Cir. 1993) (explaining that district court abuses its
discretion by failing "adequately to take into account judicially recog-
nized factors constraining" the exercise of its discretion or by basing
its decision on "erroneous factual or legal premises").

V.

In sum, we hold that the district court correctly ruled that Coal Act
premiums are taxes, that the district court erred in dismissing Count
One on claim preclusion grounds, and that the district court erred in
denying Pittston's motion to amend its complaint. Accordingly, we
reverse and remand for further proceedings consistent with this opin-
ion.

REVERSED AND REMANDED

                     18
NIEMEYER, Circuit Judge, dissenting:

The Pittston Company had its day in court in the Northern District
of Alabama in connection with its obligation, for the years 1993,
1994, and onward, to pay "premiums" or "taxes" to the United Mine
Workers of America Combined Benefit Fund (the "Combined Fund"),
created under 26 U.S.C. § 9702. It should not now, in this action, be
permitted to relitigate its obligation in connection with those same
transactions based on new theories. As explained further below, I
believe that the district court was correct in determining that Pittston's
claim in this case to declare the premiums or taxes unconstitutional
is barred by principles of res judicata.

More fundamentally, however, we do not have jurisdiction over
this action, which Pittston characterizes as a tax refund action. Section
1346(a)(1) of Title 28, on which Pittston relies for jurisdiction, waives
sovereign immunity for tax refund suits by conferring jurisdiction on
district courts over claims against the United States for the recovery
of taxes. Because Pittston paid no taxes to the United States, it cannot
"recover" taxes from the United States under§ 1346(a)(1).

For both of these reasons, I would affirm.

I

Litigation of this dispute over Combined Fund premiums began in
April 1994 when Pittston and other coal operators brought suit in the
Northern District of Alabama, challenging the computation of premi-
ums they were obligated to pay the Combined Fund under the Coal
Industry Retiree Health Benefit Act (the "Coal Act"), 26 U.S.C.
§ 9701 et seq. In that action, Pittston alleged that the United States
erroneously computed the amounts payable to the Combined Fund
under the Coal Act and that, as a result, it was required "to pay a pre-
mium approximately 10% greater than that authorized under the
[Coal] Act." It requested that the United States be ordered to "recom-
pute the initial premium [for 1993] and all subsequent premiums"
payable to the Combined Fund. The Alabama district court agreed
with Pittston and ordered the United States to recompute the premi-
ums payable by Pittston to the Combined Fund and directed the
United States to notify the Combined Fund "of the premium amount

                     19
that the Combined Fund should have assessed" for the years 1993 and
1994. At that point, the Combined Fund had not been named a defen-
dant in the Alabama action even though it had assessed and collected
the premiums required to be paid. The decision in the Alabama case
was appealed to the Eleventh Circuit, which affirmed. See National
Coal Ass'n v. Chater, 81 F.3d 1077 (11th Cir. 1996). Thereafter, the
plaintiffs in the Alabama action brought suit against the Combined
Fund, seeking a refund, with interest, of the excess payments. After
Pittston voluntarily withdrew from that action, its co-plaintiffs won a
judgment for a refund of the amounts sought. See National Mining
Ass'n v. Apfel, No. 96-1385 (N.D. Ala. Feb. 10, 1999).

In connection with the same premiums paid for the same years,
Pittston filed the action in this case, amplifying its claim of illegality
by asserting constitutional claims. In Count I of this action, Pittston
challenges the constitutionality of the Coal Act because it "places
government powers and federal revenues in the hands of a private
entity," the trustees of the Combined Fund. On the basis of these alle-
gations, Pittston requests "a refund" from the United States of all
"taxes or other sums" ever paid by Pittston to the Combined Fund. In
Count II, Pittston alleges that the United States erroneously calculated
the amounts that Pittston was required to pay to the Combined Fund
for the years 1993, 1994, and 1995, requesting "a refund" from the
United States of all "taxes or other sums" paid by Pittston to the Com-
bined Fund "in excess of the statutory formula" for the years 1993-95.
Following the judgment in favor of Pittston's former co-plaintiffs in
the second Alabama suit and prior to this appeal, Count II of this
action was settled, leaving only Count I for our consideration. On this
count, the district court dismissed the claim because it arose out of the
same transaction as the claim in the first Alabama case and therefore
was barred by res judicata. See In re Varat Enterprises, Inc., 81 F.3d
1310, 1316 (4th Cir. 1996) ("Generally, claims are part of the same
cause of action when they arise out of the same transaction or series
of transactions or the same core of operative facts" (internal citations
omitted)).

II

I turn first to our subject matter jurisdiction. Pittston invokes the
tax refund statute as the basis for this suit, styling its action as one to

                      20
recover taxes from the United States. The United States, on the other
hand, contends that the tax refund statute, 28 U.S.C. § 1346(a)(1),
does not vest district courts with jurisdiction over claims for the "res-
titution" of assessments that are neither paid to the United States nor
intended to support the United States. Section 1346(a)(1) provides
that the district courts shall have jurisdiction of:

          Any civil action against the United States for the recovery
          of any internal-revenue tax alleged to have been erroneously
          or illegally assessed or collected, or any penalty claimed to
          have been collected without authority or any sum alleged to
          have been excessive or in any manner wrongfully collected
          under the internal-revenue laws.

To support its argument that we have jurisdiction over its suit
against the United States, Pittston relies on our decision in In re
Leckie Smokeless Coal Co., 99 F.3d 573, 583 (4th Cir. 1996) (holding
that Coal Act premiums are taxes). It argues that because premiums
are taxes, it can sue the United States under 28 U.S.C. § 1346(a)(1)
for a refund of taxes.

While we did hold in Leckie that Coal Act premiums are taxes, this
holding does not end the inquiry here whether we have jurisdiction
under § 1346(a)(1). Our decision in Leckie established that Coal Act
premiums are taxes for purposes of the Anti-Injunction Act, 26 U.S.C.
§ 7421, and the Declaratory Judgment Act, 28 U.S.C. § 2201. Simi-
larly, we have determined that Coal Act premiums are taxes entitled
to priority over unsecured claims under the Bankruptcy Code, 11
U.S.C. §§ 503, 507. See Adventure Resources, Inc. v. Holland, 137
F.3d 786, 794 (4th Cir. 1998). However, we have not, thus far, deter-
mined whether Coal Act premiums are subject to recovery under
§ 1346(a)(1) as taxes "erroneously or illegally assessed or collected."
This determination must be made, just as our prior determinations
were made, by taking into consideration the context, policies, and
objectives of the pertinent statutes -- here, the tax refund statute and
the Coal Act. See King v. St. Vincent's Hospital , 502 U.S. 215, 221
& n.10 (1991) (the meaning of statutory term depends on context);
United States v. Reorganized C F & I Fabricators of Utah, Inc., 518
U.S. 213, 220-24 (1996) (the term "tax" may have different meanings
in the Internal Revenue Code and the Bankruptcy Code).

                     21
Accepting for purposes of discussion that the premiums paid to the
Combined Fund are taxes for purposes of 28 U.S.C.§ 1346(a)(1), a
suit based on that provision nevertheless must be against the United
States for the recovery from the United States Treasury of such tax
payments. The suit before us is not for such a refund. The United
States neither collected Coal Act payments nor received them, and
accordingly, a money judgment of the sort sought by Pittston would
effect a recovery from the government of something it does not have.
Such an action could only be a general damage suit, not a refund suit
for the recovery of taxes paid, i.e. for moneys"had and received." To
allow a general damage action against the United States would be
inconsistent with both the structure and the purpose of 28 U.S.C.
§ 1346(a)(1). The Supreme Court has explained that § 1346(a)(1) was
intended to "mirror" the common-law action of assumpsit brought
against private tax collectors for monies "had and received" by the
collector. United States v. Williams, 514 U.S. 527, 532 (1995); see
also Flora v. United States, 362 U.S. 145 (1960). The Court of Fed-
eral Claims, which shares jurisdiction over tax refund suits, has simi-
larly referred to the tax refund suits within its jurisdiction as "those
in which `the government has the citizen's money in its pocket.'"
Eastport S.S. Corp. v. United States, 372 F.2d 1002, 1008 (Ct. Cl.
1967) (quoting Clapp v. United States, 117 F. Supp. 576, 580 (Ct. Cl.
1954)) (emphasis added). Moreover, the statutory scheme governing
tax refund suits confirms that § 1346 is intended only as a vehicle to
recover funds "had and received" by the United States Treasury. This
is made clear by the requirement that any plaintiff bringing suit under
this section first file an administrative claim with the Secretary of the
Treasury. See 26 U.S.C. § 7422.

By interpreting § 1346(a)(1) to provide jurisdiction for this claim
by Pittston, the majority expands the waiver of sovereign immunity
beyond that authorized by Congress. See Williams , 514 U.S. at 531.
In doing so, it violates the established principle that when a statute
waives sovereign immunity, it must be strictly construed, and any
ambiguity must be resolved in favor of preserving the government's
immunity from suit. See id.; Lane v. Pena, 518 U.S. 187, 192 (1996);
United States v. Nordic Village, Inc., 503 U.S. 30, 33-34 (1992);
Schon v. United States, 759 F.2d 614, 617 (7th Cir. 1985) (Section
1346(a)(1) "is a narrow waiver of sovereign immunity, and accord-
ingly we construe it strictly").

                     22
In enacting the Coal Act, Congress provided a means for obtaining
premium refunds from the Combined Fund, the entity that collects
and receives the premium payments. See 26 U.S.C. § 9706(f)(3)(A)
(providing procedure for refunds by Combined Fund); 26 U.S.C.
§ 9702(a)(3)(C) (designating Combined Fund as a multiemployer plan
subject to ERISA); 29 U.S.C. § 1103(c)(2)(A)(ii) (providing for
recovery by employers of payments made to ERISA multiemployer
plans). This is the refund procedure to which Pittston should be remit-
ted. Significantly, Pittston's former co-plaintiffs in the Alabama
action availed themselves of the remedies against the Combined Fund
established by the Coal Act and, as noted above, succeeded in obtain-
ing a judgment against the Combined Fund. See National Mining
Ass'n, No. 96-1385 (N.D. Ala. Feb. 10, 1999). Limiting Pittston and
other aggrieved coal operators to the remedies established by the Coal
Act would be consistent with the statutory design of the Coal Act,
which was meant to "provide for the continuation of a privately
financed self-sufficient program." Pub. L. No. 102-486,
§ 19142(b)(3), 106 Stat. 3036, 3037 (1992).

Pointing to our holding in Leckie, the majority asserts that "a deci-
sion that a [Coal Act] premium is a tax for the purposes of the Anti-
Injunction and Declaratory Judgment Acts necessarily is a decision
that an objection to that assessment must be litigated in a tax refund
action." Ante, at 12. But the only necessary implication of Leckie is
that, since a coal operator's objection cannot be litigated in a suit for
injunctive or declaratory relief, some post-deprivation remedy must
be available. Congress sensibly provided such a remedy under the
Coal Act, and the federal fisc should not be exposed to a liability that
Congress clearly intended would belong to the Combined Fund.

But whether or not Pittston elects to sue the Combined Fund for its
refund, it cannot sue the United States for a refund, relying on 28
U.S.C. § 1346(a)(1) for its jurisdiction.

III

Quite apart from this fatal jurisdictional deficiency, Pittston's suit
is also barred by applicable principles of res judicata. Both the pres-
ent action and the earlier action filed in the Northern District of Ala-
bama contest the validity of the Coal Act premiums Pittston has been

                     23
obligated to pay. Indeed, both actions not only challenge the obliga-
tion to pay all past premiums, but also future premiums that could be
assessed.

The doctrine of res judicata is intended to promote judicial econ-
omy and finality by requiring a plaintiff to advance in a single action
all of the legal theories and demands for relief arising out of the same
cause of action. The doctrine applies "even though the plaintiff is pre-
pared in the second action (1) [t]o present evidence or grounds or the-
ories of the case not presented in the first action or (2) [t]o seek
remedies or forms of relief not demanded in the first action."
Restatement (Second) of Judgments § 25. A challenge to the constitu-
tionality of a statute can and should be brought in the same action
alleging the misapplication of that statute. Cf. Chicot Cty. Drainage
Dist. v. Baxter State Bank, 308 U.S. 371, 375 (1940) (Res judicata
bars litigant from raising a constitutional challenge to a statutory
scheme governing the conduct at issue in a prior case where the prior
litigation proceeded "on the assumption by all parties and the court
itself that the statute was valid"); 46 Am. Jur. 2d Judgments § 569
(1994) ("[E]ven though the constitutionality of the statute is merely
assumed in the earlier action, the judgment is nevertheless operative
to prevent a relitigation of the same cause of action"); 18 Wright, Mil-
ler & Cooper, Federal Practice and Procedure§ 4411, at 92 ("The
short of the matter is that theories arising from different sources of
law may be blended into a single claim that must be asserted on pain
of preclusion").

This circuit has followed the transactional approach to claim pre-
clusion adopted by the Restatement (Second) of Judgments. See Keith
v. Aldridge, 900 F.2d 736, 740 (1990). Pursuant to this approach, we
have held that claim preclusion operates to bar"litigation by the
plaintiff in a subsequent action of claims `with respect to all or any
part of the transaction, or series of connected transactions, out of
which the [first] action arose.'" Harnett v. Billman, 800 F.2d 1308,
1314 (4th Cir. 1986) (quoting Restatement (Second) of Judgments
§ 24).

In the earlier suit decided in Alabama, Pittston obtained a declara-
tory judgment in its favor and a final injunction directing the United
States to recalculate the premiums payable under the Coal Act, both

                    24
for past and for future premiums, and to notify the Combined Fund
of the revised calculations. Pittston's claim in this action merely seeks
further relief with respect to these same transactions. Moreover, its
contention that the premiums it paid were imposed pursuant to an
unconstitutional statute could have been advanced in the earlier suit.
Even though Pittston was the "master of its complaint" and even
though its constitutional claims were available, it chose not to raise
them at that time, and the claims are therefore now barred by res
judicata. See Brown v. Felsen, 442 U.S. 127, 131 (1979) (Res
judicata bars previously available claims "regardless of whether they
were asserted or determined in the prior proceeding"); Dionne v.
Mayor and City Council of Baltimore, 40 F.3d 677, 683 (4th Cir.
1994) (claim preclusion "forc[es] a plaintiff to raise all possible theo-
ries of recovery and to demand all desired remedies in one proceeding
at peril of losing all not raised in it").

At bottom, Pittston's various challenges to the imposition of Coal
Act premiums and its various claims for refunds arise out of the same
transactions and the same set of operative facts-- the payment of pre-
miums to the Combined Fund for the periods from 1993 forward.
These challenges and claims could have been presented in the Ala-
bama action. Accordingly, they are barred from being asserted now
in this action.

Therefore, both because of our lack of subject matter jurisdiction
and because of the bar imposed by res judicata principles, I would
affirm the judgment of the district court. I therefore respectfully dis-
sent.

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