Document ID: ./input/supremecourt_opinions/opinions/19pdf/18-587_5ifl.pdf
Page Number: 18.0

Cite as:  591 U. S. ____ (2020) 

13 

Opinion of the Court 

removal order. 

With  these  preliminary  arguments  out  of  the  way,  we

proceed to the merits. 

III 
A 
Deciding  whether  agency  action  was  adequately  ex-
plained  requires,  first,  knowing  where  to  look  for  the 
agency’s explanation.  The natural starting point here is the 
explanation provided by Acting Secretary Duke when she 
announced the rescission in September 2017.  But the Gov-
ernment urges us to go on and consider the June 2018 mem-
orandum  submitted  by  Secretary  Nielsen  as  well.  That 
memo was prepared after the D. C. District Court vacated 
the Duke rescission and gave DHS an opportunity to “reis-
sue a memorandum rescinding DACA, this time providing 
a fuller explanation for the determination that the program
lacks statutory and constitutional authority.”  298 F. Supp. 
3d, at 245.  According to the Government, the Nielsen Mem-
orandum is properly before us because it was invited by the
District  Court  and  reflects  the  views  of  the  Secretary  of 
Homeland  Security—the  official  responsible  for  immigra-
tion policy.  Respondents disagree, arguing that the Nielsen 
Memorandum, issued nine months after the rescission, im-
permissibly asserts prudential and policy reasons not relied 
upon by Duke. 

It is a “foundational principle of administrative law” that 
judicial review of agency action is limited to “the grounds
that the agency invoked when it took the action.”  Michigan, 
576 U. S., at 758.  If those grounds are inadequate, a court 
may remand for the agency to do one of two things: First, 
the  agency  can  offer  “a  fuller  explanation  of  the  agency’s 
reasoning at the time of the agency action.”  Pension Benefit 
Guaranty  Corporation  v.  LTV  Corp.,  496  U. S.  633,  654 
(1990)  (emphasis  added).  See  also  Alpharma,  Inc.  v.