The Supreme Court has blocked a lower-court ruling in a redistricting dispute in North Dakota that would gut a landmark federal civil rights law for millions of people.

Native American tribes in North Dakota challenged a state legislative map they said dilutes their voting power. An appeals court said they can't sue.

The U.S. Supreme Court threw out on Monday judicial decisions that favored transgender people in cases from North Carolina, West Virginia, Idaho and Oklahoma, including in legal challenges to state health insurance programs that deny coverage for patients seeking gender-affirming medical treatment.