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

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

15 

Opinion of the Court 

Respondents  16.  First,  after  the  decision,  EPA  informed 
the Court of Appeals that it does not intend to enforce the 
Clean Power Plan because it has decided to promulgate a 
new  Section  111(d)  rule.    Second,  on  EPA’s  request,  the 
lower court stayed the part of its judgment that vacated the
repeal,  pending  that  new  rulemaking.    “These  circum-
stances,” says the Government, “have mooted the prior dis-
pute as to the CPP Repeal Rule’s legality.”  Id., at 17 (em-
phasis added).

That Freudian slip, however, reveals the basic flaw in the
Government’s argument: It is the doctrine of mootness, not 
standing, that addresses whether “an intervening circum-
stance [has] deprive[d] the plaintiff of a personal stake in 
the outcome of the lawsuit.”  Genesis HealthCare Corp. v. 
Symczyk, 569 U. S. 66, 72 (2013) (internal quotation marks 
omitted); see also Friends of the Earth, Inc. v. Laidlaw En-
vironmental  Services  (TOC),  Inc.,  528  U. S.  167,  189–192 
(2000).  The distinction matters because the Government, 
not petitioners, bears the burden to establish that a once-
live case has become moot.  Id., at 189; Adarand Construc-
tors, Inc. v. Slater, 528 U. S. 216, 222 (2000) (per curiam).

That  burden  is  “heavy”  where,  as  here,  “[t]he  only  con-
ceivable basis for a finding of mootness in th[e] case is [the 
respondent’s] voluntary conduct.”  Friends of the Earth, 528 
U. S., at 189.  Although the Government briefly argues that 
the lower court’s stay of its mandate extinguished the con-
troversy,  it  cites  no  authority  for  that  proposition,  and  it
does  not  make  sense:  Lower  courts  frequently  stay  their 
mandates  when  notified  that  the  losing  party  intends  to
seek our certiorari review.  So the Government’s mootness 
argument boils down to its representation that EPA has no 
intention of enforcing the Clean Power Plan prior to prom-
ulgating a new Section 111(d) rule.

But “voluntary cessation does not moot a case” unless it 
is  “absolutely  clear  that  the  allegedly  wrongful  behavior