Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-451_7m58.pdf
Page Number: 94

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

13 

KAGAN, J., dissenting 

experience;  and  to  involve  policy  choices,  including  cost-
benefit assessments and trade-offs between conflicting val-
ues.  So  a  court  without  relevant  expertise  or  experience, 
and  without  warrant  to  make  policy  calls,  appropriately 
steps back.  The court still has a role to play: It polices the
agency to ensure that it acts within the zone of reasonable 
options.  But the court does not insert itself into an agency’s
expertise-driven,  policy-laden  functions.  That  is  the  ar-
rangement best suited to keep every actor in its proper lane. 
And it is the one best suited to ensure that Congress’s stat-
utes work in the way Congress intended. 

The majority makes two points in reply, neither convinc-
ing.  First, it insists that “agencies have no special compe-
tence” in filling gaps or resolving ambiguities in regulatory 
statutes;  rather,  “[c]ourts  do.”   Ante,  at  23.  Score  one  for 
self-confidence;  maybe  not  so  high  for  self-reflection  or 
-knowledge.   Of  course  courts  often  construe  legal  texts,
hopefully  well.  And  Chevron’s  first  step  takes  full  ad-
vantage of that talent: There, a court tries to divine what
Congress meant, even in the most complicated or abstruse
statutory schemes.  The deference comes in only if the court 
cannot do so—if the court must admit that standard legal
tools will not avail to fill a statutory silence or give content 
to  an  ambiguous  term.    That  is  when  the  issues  look  like 
the ones I started off with: When does an alpha amino acid
polymer  qualify  as  a  “protein”?    How  distinct  is  “distinct” 
for squirrel populations?  What size “geographic area” will
ensure  appropriate  hospital  reimbursement?    As  between 
two equally feasible understandings of “stationary source,”
should one choose the one more protective of the environ-
ment or the one more favorable to economic growth?  The 
idea that courts have “special competence” in deciding such
questions whereas agencies have “no[ne]” is, if I may say,
malarkey.    Answering  those  questions  right  does  not 
mainly demand the interpretive skills courts possess.  In-
stead, it demands one or more of: subject-matter expertise,