Document ID: ./input/supremecourt_opinions/opinions/10pdf/09-1233.pdf
Page Number: 47.0

Cite as:  563 U. S. ____ (2011) 

41 

Opinion of the Court 

prison  officials.    The  court  was  not  required  to  second-
guess  the  exercise  of  that  discretion.    Courts  should  pre-
sume  that  state  officials  are  in  a  better  position  to  gauge 
how best to preserve public safety and balance competing 
correctional  and  law  enforcement  concerns.    The  decision 
to leave details of implementation to the State’s discretion 
protected  public  safety  by  leaving  sensitive  policy  deci-
sions to responsible and competent state officials. 

During  the  pendency  of  this  appeal,  the  State  in  fact 
began to implement measures to reduce the prison popula-
tion.  See  Supp.  Brief  for  Appellants  1.    These  measures 
will  shift  “thousands”  of  prisoners  from  the  state  prisons
to the county jails by “mak[ing] certain felonies punishable 
by  imprisonment  in  county  jail”  and  “requir[ing]  that 
individuals  returned  to  custody  for  violating  their  condi-
tions  of  parole  ‘serve  any  custody  term  in  county  jail.’ ”  
Ibid.  These developments support the three-judge court’s
conclusion  that  the  prison  population  can  be  reduced  in
a manner calculated to avoid an undue negative effect on
public safety. 

III 

Establishing  the  population  at  which  the  State  could 
begin  to  provide  constitutionally  adequate  medical  and
mental health care, and the appropriate time frame within
which  to  achieve  the  necessary  reduction,  requires  a  de-
gree  of  judgment.  The  inquiry  involves  uncertain  predic-
tions  regarding  the  effects  of  population  reductions,  as
well  as  difficult  determinations  regarding  the  capacity  of 
prison  officials  to  provide  adequate  care  at  various  popu-
lation  levels.    Courts  have  substantial  flexibility  when 
making these judgments.  “ ‘Once  invoked, “the scope of a 
district  court’s  equitable  powers  . . .  is  broad,  for  breadth 
and  flexibility  are  inherent  in  equitable  remedies.” ’ ” 
Hutto, 437 U. S., at 687, n. 9 (quoting Milliken v. Bradley, 
433  U. S.  267,  281  (1977),  in  turn  quoting  Swann  v.