Missouri voters blocked a GOP-drawn congressional map from going into effect for future elections via a ballot measure, NBC News projects.

The result is a blow for Republicans, who fought for more than a year to carve up one of the state’s two-Democratic-held districts.

The vote was the culmination of a long-running political and legal fight. Missouri is one of the GOP-led states that heeded President Donald Trump’s mid-decade redistricting call, passing new lines last year that drew longtime Democratic Rep. Emanuel Cleaver into a heavily Republican district.

In response, a group called People Not Politicians Missouri said it gathered more than 300,000 signatures — well above the 106,000 necessary — to place a referendum on the ballot that gave voters the opportunity to veto the map.

Legislation facing such a referendum is typically put on hold until voters have weighed in, but Missouri Republicans fought to put the map in place for this year’s midterms. State Secretary of State Denny Hoskins, a Republican, waited until the statutory deadline in August to announce that he wouldn’t certify the referendum for the November ballot, saying it was unconstitutional.

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The issue ricocheted through the state and federal court systems, at times producing conflicting rulings. Ultimately, the U.S. Supreme Court rejected Missouri Republicans’ attempts to use the redrawn map for this year’s elections three times.

Nine states enacted new congressional maps ahead of the 2026 midterms, outside the traditional process that occurs every 10 years after the new census. The mid-decade redistricting battle is expected to extend into the next election cycle, with Democratic-led states continuing to try to counteract Trump’s initial push and Republican-led states responding to a major Supreme Court ruling this year that opened the door to dismantling majority-Black districts represented by Democrats.