The Missouri Supreme Court on Sept. 3 unanimously blocked a congressional map backed by President Donald Trump from being used in the Nov. 3 midterm elections and ordered a statewide referendum on the plan.

The ruling, which may hinder Republican efforts to maintain their majority in the U.S. House of Representatives, could help longtime Rep. Emanuel Cleaver (D-Mo.) retain his seat. His Kansas City-based district had been broken up under the redrawn map.

Missouri’s mid-decade redistricting is among the most heavily litigated in the country. Roughly a dozen lawsuits have landed in various courts over the past year.

The fight began last year, when Republican Gov. Mike Kehoe called lawmakers into a special session in late August 2025. Trump had called on GOP-led states to reshape districts ahead of the midterms.

On Sept. 28, 2025, Kehoe signed the redistricting plan approved during the special session into law. A group called People Not Politicians gathered signatures throughout the fall and turned in a petition on Dec. 9, 2025, seeking to put a question on the ballot challenging the plan. The group gathered more than 305,000 signatures, well over the roughly 110,000 that were required.

On Aug. 4, 2026, the day of the primary election, Missouri Secretary of State Denny Hoskins rejected the petition, arguing that the Missouri Constitution does not allow referendums on congressional redistricting. A county circuit judge agreed and ruled in his favor on Aug. 19. Richard von Glahn, the executive director of People Not Politicians, appealed to the Missouri Supreme Court.

In the case, known as von Glahn v. Hoskins, the court ruled the map has to be approved by voters in a referendum in November before it can become effective.

In her written opinion, Judge Ginger Gooch said a citizen petition to place House Bill 1, the redistricting plan, on the ballot was “legal, sufficient, and timely,” and Hoskins “incorrectly concluded otherwise” when he disallowed the petition.

Gooch said the 2025 map approved by the state Legislature “is not the law and has never been the law.”

“There is only one valid congressional redistricting in effect—the congressional redistricting the General Assembly established in 2022,” she said.

The state high court reversed the county circuit court and issued an injunction preventing Hoskins “and all of those acting in concert with him” from implementing the congressional map included in House Bill 1.

The court’s ruling means the general election in November will be held based on the 2022 map, even though the primary election was held based on the 2025 map. If the referendum on the 2025 map is approved by voters in November, the underlying law will take effect in 30 days, allowing the map to be used in future elections.

Missouri Attorney General Catherine Hanaway said the state will seek emergency review at the U.S. Supreme Court.

“Never before in American history has a court overturned a congressional map after a primary and before a general election,” she said in a post on X.

“This unprecedented decision clearly violates federal law and has thrust our state into a full‑fledged constitutional crisis.”

Late Sept. 3, Hanaway said on X that the state had officially filed for a stay with the Missouri Supreme Court, describing it as “a necessary step before our emergency appeal” to the U.S. Supreme Court.

Trump criticized the ruling, saying it was “a Dark Day for ‘Justice’ in Missouri.”

“The Missouri Supreme Court just ridiculously ruled in favor of changing the maps back to what they were a long time ago,” Trump said in a post on Truth Social.

“The problem is, according to Legal Scholars, that not only was the ruling horrible, ridiculous, and unConstitutional, but there won’t be enough time to change the map back with the Election coming up in a very short period of time.”

Cleaver hailed the ruling, saying “democracy prevails.”

“More than 305,000 Missourians demanded a say in who will represent them in the halls of Congress,” the congressman said in a post on X.

“Despite the cynical and deeply shameful attempt to silence many of our neighbors, the people fought back and won. This reaffirms that the people should choose their politicians, not the other way around.”

Kimberly Hayek and Reuters contributed to this report.