Document ID: ./input/supremecourt_opinions/opinions/boundvolumes/558bv.pdf
Page Number: 428.0

Cite as: 558 U. S. 256 (2010) 

267 

Opinion of the Court 

We acknowledge that the standard for intervention in orig­
inal  actions  by  nonstate  entities  is  high—and  appropriately 
so.  Such  actions  tax  the  limited resources  of  this  Court  by 
requiring  us  “awkwardly  to  play  the  role  of  factﬁnder”  and 
diverting  our  attention  from  our  “primary  responsibility  as 
an appellate tribunal.”  Ohio v.  Wyandotte Chemicals Corp., 
401  U. S.  493,  498  (1971);  Maryland  v.  Louisiana,  451  U. S. 
725,  762  (1981)  (Rehnquist,  J.,  dissenting).  In  order  to  en­
sure  that  original  actions  do  not  assume  the  “dimensions  of 
ordinary  class  actions,”  New  Jersey  v.  New  York,  345  U. S., 
at  373, we  exercise  our  original jurisdiction  “sparingly”  and 
retain “substantial discretion” to decide whether a particular 
claim requires “an original forum in this Court,” Mississippi 
v.  Louisiana,  506  U. S.  73,  76  (1992)  (internal  quotation 
marks omitted). 

Respect for state sovereignty also calls for a high thresh­
old to intervention by nonstate parties in a sovereign dispute 
committed  to  this  Court’s  original  jurisdiction.  Under  28 
U. S. C.  § 1251,  this  Court  exercises  “original  and  exclusive” 
jurisdiction  to  resolve  controversies  between  States  that,  if 
arising  among  independent  nations,  “would  be  settled  by 
treaty  or  by  force.”  Kansas  v.  Colorado,  206  U. S.  46,  98 
(1907).  This Court has described its original jurisdiction as 
“delicate  and  grave,”  Louisiana  v.  Texas,  176  U. S.  1,  15 
(1900),  and  has  guarded  against  its  use  as  a  forum  in  which 
“a  state  might  be  judicially  impeached  on  matters  of  policy 
by its own subjects,” New Jersey v.  New York, supra, at 373. 
In its sovereign capacity, a State represents the interests of 
its  citizens  in  an  original  action,  the  disposition  of  which 
binds the citizens.  Nebraska v.  Wyoming, supra, at 22; New 
Jersey  v.  New  York,  345  U. S.,  at  372–373.  A  respect  for 
sovereign dignity, therefore, counsels in favor of restraint in 
allowing  nonstate  entities  to  intervene  in  such  disputes. 
See  ibid.;  accord,  United  States  v.  Texas,  143  U. S.  621,  643 
(1892)  (“[E]xclusive  jurisdiction  was  given to  this  court,  be­
cause  it  best  comported  with  the  dignity  of  a  State,  that  a