Supreme Court rules roughly half of Oklahoma is tribal reservation

The Supreme Court ruled 5-4 on Thursday that nearly half of Oklahoma is a Native American reservation "in the eyes of the criminal justice system," the New York Times reports.

Why it matters: The decision prevents the state from being able to prosecute offenses in the Creek Nation reservation that involve Native Americans, per the Times.

Details: Jimcy McGirt, a Muscogee (Creek) Nation member convicted of molesting a child by state authorities, argued to the court that only the federal government could prosecute him because "Congress had never clearly destroyed the sovereignty of the Creek Nation over the area," per the Times.

What they're saying: The National Congress of American Indians (NCAI) and Native American Rights Fund released a statement on Thursday in support of the court's decision.

• NCAI president Fawn Sharp said that "this question has loomed over federal Indian law" for two Supreme Court terms. "This morning, NCAI joins the rest of Indian Country in congratulating the Muscogee (Creek) Nation and proudly asserting that its lands remain, and will forever be considered, Indian country — as guaranteed in their treaty relationship with the United States."
• Democrats on the House Energy and Natural Resources Committee tweeted that the ruling is "a step towards making amends for centuries of paternalism, violence & neglect towards Native Americans."
• Sen. James Lankford (R-Okla.) released a statement on Thursday saying he looked forward to working with the five tribes affected by the ruling "to craft legislation that ensures that the ruling has a minimal impact on individuals and businesses throughout Oklahoma."
• Sen. Jim Inhofe (R-Okla.) said that, moving forward, the focus will be working with tribal and state officials "to find a workable solution for everyone that ensures criminals are prosecuted and brought to justice in the most appropriate manner."

What's next: Practical consequences for 1.8 million state residents affected by the ruling are vast, "with justices asking in oral arguments how business disputes and adoptions would be affected," per the Times.