WASHINGTON — For the third time, the Supreme Court on Friday shut down efforts by Missouri Republicans to use a new congressional map in the midterm elections that are already underway.

The court blocked an appeals court ruling that sought to revive the 2025 map despite two previous Supreme Court decisions and a ruling by the Missouri Supreme Court that ruled against Republicans on the same issue. There were no dissents.

“At this late date, ordering reversion to the 2025 map in the midst of an ongoing election would usher in electoral chaos,” the ruling said.

In doing so, the justices granted an emergency application filed by People Not Politicians, the group challenging the new map.

The election will proceed using a 2022 map that includes six seats held by Republicans and two held by Democrats. The state has already started sending out ballots to military and overseas voters, and some absentee voting began Tuesday.

The high court cited the fact that Missouri has already begun its voting processes in its argument.

“This Court has repeatedly cautioned that ‘lower federal courts should not ‘alter the election rules’’ of a state ‘on the eve of an election,’” the ruling said. “The election is not merely upcoming; it has already started.”

The proposed 2025 map would have eliminated one of the Democratic seats, held by Rep. Emanuel Cleaver.

The Missouri map was part of a nationwide push by Republicans at the urging of President Donald Trump to draw new congressional districts that would favor their candidates. Democrats in other states, including California, responded by drawing new maps, too.

The St. Louis-based 8th U.S. Circuit Court of Appeals on Monday ruled that the Republican-drawn Missouri map could be used, but it never went into effect. The Supreme Court’s ruling Tuesday overturns that decision.

The appeals court had ruled the state had to use the 2025 map in part because the primary election had already taken place using it. But in a conflicting ruling, the Missouri Supreme Court said the 2022 map had to be used, while making it clear that Missouri Secretary of State Denny Hoskins, a Republican, was to blame for the confusion.

The state high court ultimately held Hoskins in contempt for his actions.

In its ruling on Friday, the Supreme Court wrote that Hoskins “was well aware that conducting the August primary election with the 2025 map carried significant risks,” citing a May opinion from the state high court that made clear the new map would not go into effect ahead of the 2026 elections.

The court battle started after opponents of the new map gained enough signatures to trigger a state referendum on whether it should be used. Under state law, whenever a state law is subject to a referendum, it is suspended until after the vote takes place.

But Hoskins delayed a decision on whether the referendum push was legitimate until the eve of the primary. He rejected the proposal and ordered the new map to be used.

The Missouri Supreme Court then quickly ruled that there were no grounds to reject the referendum proposal and that, with the issue being put to voters in November, the map should be put on hold and the 2022 districts used instead.

The litigation seemed to be over until a new lawsuit was filed on Sept. 4 by Rick Brattin, the Republican nominee in the district held by Cleaver, as well as Rep. Bob Onder, R-Mo., and two voters.

That moved the fight into federal court, where Missouri-based U.S. District Judge Stephen Clark ruled that the new map should be used. That decision ultimately led to the appeals court ruling and Supreme Court intervention.