Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 83

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

27 

KAGAN, J., dissenting 

faith with that congressional choice, courts must give agen-
cies  “ample  latitude”  to  revisit,  rethink,  and  revise  their
regulatory approaches.  Ibid.  So it is here.  Section 111(d) 
was written, as I’ve shown, to give EPA plenty of leeway. 
See supra, at 6–8.  The enacting Congress told EPA to pick 
the “best system of emission reduction” (taking into account
various factors).  In selecting those words, Congress under-
stood—it had to—that the “best system” would change over 
time.  Congress wanted and instructed EPA to keep up.  To 
ensure the statute’s continued effectiveness, the “best sys-
tem”  should  evolve  as  circumstances  evolved—in  a  way 
Congress knew it couldn’t then know.  See Massachusetts, 
549 U. S., at 532.  EPA followed those statutory directions 
to  the  letter  when  it  issued  the  Clean  Power Plan.    It  se-
lected  a  system  (as  the  regulated  parties  agree)  that
achieved  greater  emissions  reductions  at  lower  cost  than 
any  technological  alternative  could  have,  while  maintain-
ing a reliable electricity market.  Even if that system was
novel, it was in EPA’s view better—actually, “best.”  So it 
was the system that accorded with the enacting Congress’s 
choice. 

And  contra  the  majority,  it  is  that  Congress’s  choice 
which counts, not any later one’s.  The majority says it “can-
not ignore” that Congress in recent years has “considered 
and rejected” cap-and-trade schemes.  Ante, at 27–28.  But 
under normal principles of statutory construction, the ma-
jority should ignore that fact (just as I should ignore that 
Congress failed to enact bills barring EPA from implement-
ing the Clean Power Plan).  As we have explained time and 
again, failed legislation “offers a particularly dangerous ba-
sis on which to rest an interpretation of an existing law a
different and earlier Congress” adopted.  Bostock v. Clayton 
County, 590 U. S. ___, ___ (2020) (slip op., at 20) (internal
quotation marks omitted); see Sullivan v. Finkelstein, 496 
U. S. 617, 632 (1990) (Scalia, J., concurring in part) (“Argu-
ments based on subsequent legislative history” should “not