Document ID: ./input/supremecourt_opinions/opinions/19pdf/18-9526_9okb.pdf
Page Number: 38.0

Cite as:  591 U. S. ____ (2020) 

35 

Opinion of the Court 

eastern  (Indian)  and  western  (Oklahoma)  territories.    So, 
simply put, the Enabling Act sent state-law cases to state
court  and  federal-law  cases  to  federal  court.  And  serious 
crimes  by  Indians  in  Indian  country  were  matters  that
arose under the federal MCA and thus properly belonged in 
federal court from day one, wherever they arose within the
new State. 

Maybe  that’s  right,  Oklahoma  acknowledges,  but  that’s
not what happened.  Instead, for many years the State con-
tinued  to  try  Indians  for  crimes  committed  anywhere 
within its borders.  But what can that tell us?  The State 
identifies  not  a  single  ambiguous  statutory  term  in  the 
MCA  that  its  actions  might  illuminate.    And,  as  we  have 
seen, its own courts have acknowledged that the State’s his-
toric practices deviated in meaningful ways from the MCA’s 
terms.  See supra, at 22–23.  So, once more, it seems Okla-
homa asks us to defer to its usual practices instead of fed-
eral law, something we will not and may never do.

That  takes  Oklahoma  down  to  its  last  straw  when  it 
comes  to  the  MCA.  If Oklahoma  lacks  the  jurisdiction  to
try  Native  Americans  it  has  historically  claimed,  that 
means at the time of its entry into the Union no one had the 
power to try minor Indian-on-Indian crimes committed in 
Indian country.  This much follows, Oklahoma reminds us, 
because the MCA provides federal jurisdiction only for ma-
jor  crimes,  and  no  tribal  forum  existed  to  try  lesser  cases
after Congress abolished the tribal courts in 1898.  Curtis 
Act, §28, 30 Stat. 504–505.  Whatever one thinks about the 
plausibility  of  other  discontinuities  between  federal  law 
and  state  practice,  the  State  says,  it  is  unthinkable  that 
Congress  would  have  allowed  such  a  significant  “jurisdic-
tional  gap”  to  open  at  the  moment  Oklahoma  achieved 
statehood. 

But what the State considers unthinkable turns out to be 
easily  imagined.  Jurisdictional  gaps  are  hardly  foreign  to 
this area of the law.  See, e.g., Duro v. Reina, 495 U. S. 676,