Document ID: ./input/supremecourt_opinions/opinions/21pdf/21-954_7l48.pdf
Page Number: 26

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

21 

Opinion of the Court 

U. S. C. §551(4); see 20 F. 4th, at 950–951 (“The States are 
challenging  the  Termination  Decision—not  the  June  1 
Memorandum,  the  October  29  Memoranda,  or  any  other 
memo.”).  To  the  extent  that  the  Court  of  Appeals  under-
stood itself to be reviewing an abstract decision apart from 
specific agency action, as defined in the APA, that was er-
ror.  It was not the case that the June 1 Memorandum and 
the October 29 Memoranda “simply explained DHS’s deci-
sion,” while only the decision itself “had legal effect.”  Id., 
at 951.  To the contrary, the June 1 Memorandum and the 
October  29  Memoranda  were  themselves  the  operative
agency actions, each of them an “agency statement . . . de-
signed to implement, interpret, or prescribe law or policy.”
5 U. S. C. §551(4).

Second, and relatedly, respondents characterized the Oc-
tober  29  Memoranda  as  post hoc  rationalizations  of  the 
June 1 Memorandum under our decision in Regents.  Brief 
for  Respondents  40  (“[T]he  [October  29]  Memoranda  are 
nothing  more  than  improper,  post hoc  rationalizations  for 
terminating MPP.”); see also 20 F. 4th, at 961 (questioning
how the October 29 Memoranda “[could] be anything more 
than  post hoc  rationalizations  of  the  Termination  Deci-
sion”).  But  Regents  involved  the  exact  opposite  situation 
from this one.  There, as here, DHS had attempted to re-
scind a prior administration’s immigration policy, but a Dis-
trict  Court  found  the  rescission  inadequately  explained.
Faced  with  the  same  two  options  outlined  above,  then- 
Secretary  Nielsen  elected  the  first  option  rather  than  the 
second.  That is, she chose to “rest on the [original] Memo-
randum while elaborating on [her] prior reasoning,” rather
than “issue a new rescission bolstered by new reasons ab-
sent  from  the  [original]  Memorandum.”  591  U. S.,  at  ___ 
(slip  op.,  at  14).   As  such,  her  elaboration  “was  limited  to 
the agency’s original reasons,” and was “ ‘viewed critically’ 
to ensure that the rescission [was] not upheld on the basis 
of impermissible ‘post hoc rationalization.’ ”  Id., at ___–___