Document ID: ./input/supremecourt_opinions/opinions/23pdf/23a349_0813.pdf
Page Number: 22.0

Cite as:  603 U. S. ____ (2024) 

19 

Opinion of the Court 

that the agency’s “procedural determinations” may be sub-
ject  to  harmless-error  review,  §7607(d)(8),  the  Act  also 
seems to treat separately challenges to agency “actions” like 
the FIP before us, authorizing courts to “reverse any . . . ac-
tion,” found to be “arbitrary” or “capricious,” §7607(d)(9)(A) 
(emphasis  added).    With  so  many  reasons  for  caution,  we 
think sticking to our normal course of declining to consider 
forfeited arguments the right course here.14 

* 
  The  applications  for  a  stay  in  Nos.  23A349,  23A350, 
23A351,  and  23A384  are  granted.    Enforcement  of  EPA’s 
rule against the applicants shall be stayed pending the dis-
position of the applicants’ petitions for review in the United 
States Court of Appeals for the D. C. Circuit and any peti-
tion  for  writ  of  certiorari,  if  such  writ  is  timely  sought.  
Should the petition for certiorari be denied, this order will 
terminate automatically.  If the petition is granted, this or-
der shall terminate upon the sending down of the judgment 
of this Court. 

It is so ordered. 

—————— 

14 Admittedly, the dissent points to some statements in the FIP sug-
gesting  EPA  considered  nationwide  data  in  parts  of  its  analysis.    See, 
e.g., post, at 14; see also, e.g., 88 Fed. Reg. 36721, 36727.  But other state-
ments in that rule and supporting documents also seem to suggest EPA 
considered  state-specific  information.    See  Part  I–C,  supra.    If,  as  the 
dissent posits, only nationwide data informed EPA’s analysis, why would 
EPA say that, “for purposes of identifying the appropriate level of con-
trol,” it focused on “the 23 upwind states that were linked” to the down-
wind States, rather than, say, “all states in the contiguous U.S.”?  Final 
Ozone Analysis 3 (footnote omitted).  Why would EPA explain that its 
“findings regarding air quality improvement” downwind were a “central 
component”  of  picking  the  appropriate  cost  levels  and  so  defining  a 
State’s  significant  contribution?    88  Fed.  Reg.  36741.    And  why  would 
EPA bother to “determine the relationship between changes in emissions 
and  changes  in  ozone  contributions  on  a  state-by-state  . . .  basis”  and 
“calibrat[e]” that relationship “based on state-specific source apportion-
ment”?  Final Ozone Analysis 43.  In asking these questions, we do not 
profess answers; we simply highlight further reasons for caution.