Missouri’s congressional redistricting dispute is heading towards a possible second Supreme Court intervention after more than 1.2 million voters took part in an August primary using the state’s 2025 map. The Eighth Circuit Court of Appeals ruled that the 2025 districts must also be used in November, saying reverting to the 2022 map after the primary could violate the Constitution, but suspended its order until 28 September to allow a Supreme Court challenge.

The Missouri Supreme Court had previously left the 2022 districts in place after allowing opponents of the 2025 map to pursue a referendum. Supporters of keeping the newer map argue that changing districts between elections could disenfranchise voters, particularly where primary candidates were unopposed, while Yale and UC Davis law professors contend the 2025 lines were never legally valid and should not be used again. Legal commentators also criticised the state’s handling of the referendum, including delays in resolving more than 300,000 submitted signatures.