Document ID: ./input/supremecourt_opinions/opinions/21pdf/21-954_7l48.pdf
Page Number: 36

Cite as:  597 U. S. ____ (2022) 

3 

ALITO, J., dissenting 

existing detention facilities could not house all the people 
who were attempting to enter unlawfully, many “illegal al-
iens with meritless asylum claims were being released into 
the United States,” and many, once released, simply “ ‘dis-
appeared.’ ” Ibid. (emphasis deleted).  To address this prob-
lem,  DHS  promulgated  the  Migrant  Protection  Protocols 
(MPP) in December of that year.  See id., at 832.  The MPP 
program relied on Congress’s express grant of authority to
“return” ”alien[s] . . . arriving on land . . . from a foreign ter-
ritory  contiguous  to  the  United  States”  “to  that  territory
pending a proceeding” to remove them to their countries of 
origin.  §1225(b)(2)(C).2    MPP  provided  that  certain  non-
Mexican nationals arriving at the United States border by
land from Mexico would be returned to Mexico to await the 
results of their removal proceedings.  The Mexican Govern-
ment  agreed  to  cooperate  and  to  accept  aliens  while  they 
awaited removal. 

While the policy was in effect, DHS issued a memoran-
dum in which it determined that MPP was “an indispensa-
ble tool in addressing the ongoing crisis at the southern bor-
der.”  App.  189  (Department  of  Homeland  Security:
Assessment  of  the  Migrant  Protection  Protocols  (Oct.  28, 
2019)).  It concluded that MPP directly reduced the number 
of aliens unlawfully released into the United States and de-
terred  others  from  attempting  to  cross  the  border  unlaw-
fully in the first place.  554 F. Supp. 3d, at 833.  DHS found 
that total border encounters decreased by 64 percent after 
MPP was implemented.  App. 189.  With MPP in place, al-
iens  who  lacked  meritorious  claims  could  no  longer  count
on  “a  free  ticket  into  the  United  States,”  and  as  a  result, 
many “voluntarily return[ed] home.”  Id., at 192.  MPP also 
helped  DHS  process  meritorious  asylum  claims  “within 
—————— 

2 That  policy  was  almost  immediately  enjoined  by  a  Federal  District
Court.  Innovation Law Lab v. Nielsen, 366 F. Supp. 3d 1110 (ND Cal. 
2019).  This Court stayed that injunction.  Wolf v. Innovation Law Lab, 
589 U. S. ___ (2020).