The U.S. Supreme Court on Tuesday declined to reinstate a Republican-drawn congressional map in Missouri, leaving the 2021 map in place for November's midterm elections and dealing a blow to GOP hopes of locking in an additional safe seat.

Justice Brett Kavanaugh, who handles emergency matters from Missouri and other states in the Eighth Circuit, rejected the state GOP's request without referring the case to the full court—a signal that the justices saw no merit in overturning the Missouri Supreme Court's unanimous September 3 ruling.

The Missouri high court, which includes five Republican-appointed judges, had blocked the new map and ordered that it be submitted to voters in a November referendum before taking effect. The decision means Missouri's eight congressional districts will be drawn according to boundaries set after the 2020 census, not the Trump-backed map passed by the Republican-controlled legislature earlier this year.

Referendum Rule Blocks GOP Map

Missouri Republicans argued the state's referendum process—which allows citizens to petition for a public vote on new laws—does not apply to redistricting. Secretary of State Jay Ashcroft, a Republican, had rejected a citizen petition seeking to put the new map to a vote, declaring redistricting exempt from the referendum clause.

The Missouri Supreme Court disagreed. "The referendum petition was legal, sufficient, and timely, and the secretary incorrectly concluded otherwise," Justice Ginger Gooch wrote for the court. The redrawn map "will not go into effect unless and until approved by voters."

The Guardian reported that the ruling effectively prevents Republicans from using the new map in the midterms, where control of the House hangs in the balance. Missouri's delegation currently includes six Republicans and two Democrats, and the new map was expected to eliminate one of the two competitive Democratic seats, potentially netting the GOP a seventh seat in a closely divided House.

Trump-Backed Map Designed to Reduce Competition

The new congressional map, drawn by the Republican legislature, consolidated Democratic voters in Kansas City and St. Louis into heavily Democratic districts while spreading suburban swing voters across surrounding rural Republican districts. Redistricting analysts said the map would likely secure GOP control of seven of Missouri's eight seats for the next decade.

Trump endorsed the map in a Truth Social post in June, calling it a "beautiful victory for election integrity" and urging Republican legislators to pass it before the midterms. The legislature complied, and Governor Eric Greitens signed it into law in July.

Democrats and voting rights groups immediately launched a referendum drive, gathering more than 160,000 signatures—well above the 106,000 required under Missouri law. But Ashcroft, citing a 1960s attorney general opinion that redistricting is a "legislative function" exempt from referendums, refused to certify the petition for the November ballot.

The Missouri Supreme Court called that interpretation unfounded. NBC News reported the court found "nothing in state law that says redistricting plans are exempt from the referendum process." The justices ordered Ashcroft to place the map on the November ballot as a statewide advisory referendum.

Kavanaugh Defers to State Court

Missouri Republicans appealed to the U.S. Supreme Court on an emergency basis, arguing the state court's ruling violated the federal Constitution's Elections Clause, which grants state legislatures exclusive authority to set rules for congressional elections. The GOP brief warned that allowing voter referendums on redistricting would create "chaos" and "uncertainty" in federal elections.

Kavanaugh rejected the argument without comment or dissent. The New York Times noted Kavanaugh's move "deferred to Missouri's Supreme Court," signaling the federal judiciary would not second-guess state court interpretations of state referendum law.

The decision contrasts with the Supreme Court's aggressive intervention in other election cases this cycle, including its 5-4 ruling last month clearing Trump's $400 million White House ballroom project and its decision to allow mail voting restrictions to take effect in three swing states. But Kavanaugh has previously expressed reluctance to override state election procedures close to an election, fearing voter confusion.

November Referendum Now in Play

Missouri voters will now decide the map's fate in a November 8 referendum held simultaneously with the midterm election. If voters approve the new map, it will take effect for the 2028 congressional races. If they reject it, the 2021 map remains in force through the 2030 census.

Al Jazeera reported the referendum outcome is uncertain. Polling shows Missourians narrowly favor the GOP-drawn map, 48% to 44%, but "undecided" voters could swing the result. Turnout dynamics will also matter: a high-turnout Democratic midterm wave could defeat the map, while strong Republican enthusiasm might carry it to passage.

The case is Missouri v. Hoskins, No. 26A123. The decision leaves Missouri Republicans without the redistricting advantage they had counted on to pad their House majority ahead of a midterm cycle where Democrats are defending 22 of 35 Senate seats and polling suggests a competitive House landscape.