The US Supreme Court has blocked Missouri from using a Republican-backed congressional map for the 2026 general election, leaving the state to proceed with district boundaries approved in 2022.
The decision means ballots already printed and sent to voters, including military and overseas voters, will remain valid. Absentee voting by post and in person began earlier this week.
In an unsigned opinion issued without recorded dissent, the justices said the election had already begun and warned that reinstating the 2025 map at this stage would create “electoral chaos”.
The court directed lower courts not to prevent Missouri from using the 2022 map and not to require the state to adopt the 2025 boundaries for the November 3 election.
Missouri congressional map dispute
The ruling is the latest development in a rapidly moving legal battle that has reached the Supreme Court three times. A map adopted by Missouri’s Republican-led legislature last year, and supported by President Trump, would give Republicans an advantage in seven of the state’s eight House districts.
Missouri’s current congressional delegation consists of six Republicans and two Democrats. The 2025 map splits the Kansas City area and makes Democratic Representative Emanuel Cleaver’s district more conservative.
The Supreme Court had previously prevented the new boundaries from being used in the general election. Justice Brett Kavanaugh, acting alone, first left in place a Missouri Supreme Court ruling barring their use before the justices later halted a federal district court order that would have required the state to adopt them.
The dispute returned to the Supreme Court after the US Court of Appeals for the Eighth Circuit ruled that proceeding with the 2022 districts violated the Constitution and ordered the newer map to be reinstated. A federal district judge then issued an injunction requiring Missouri’s secretary of state to use the 2025 districts.
People Not Politicians, which is challenging the newer map, argued that the appeals court had attempted to circumvent the Supreme Court’s earlier order. It warned that changing the boundaries during the election would cause confusion over how voting should be conducted and how the result should be determined.
Missouri officials, however, said using the 2022 map after voters had cast ballots in the primary under the newer districts could itself violate constitutional voting rights. They said switching maps would disenfranchise hundreds of thousands of primary voters and force candidates to campaign in districts they had not contested over the past year.
Officials also said reverting to the 2025 map would avoid disenfranchising primary voters but would breach the deadline for sending ballots to military and overseas voters, which Missouri was required to meet by September 19. Election authorities described reprinting and distributing ballots while voting was under way as “practically impossible”.
The 2025 congressional districts were used in Missouri’s August primary elections. Mr Cleaver said the Supreme Court’s ruling followed demands from more than 305,000 Missourians for a say in the matter, and claimed the redistricting effort had sought to “silence the voices of Missouri voters and steal a congressional seat”.
