Missouri voters will decide Proposition A, a veto referendum on House Bill 1, the 2025 congressional map passed by the Republican-led legislature and signed by Governor Mike Kehoe. The measure, which aims to shift the 5th district toward Republican control, reached the November 3, 2026 ballot after the Missouri Supreme Court unanimously upheld the referendum petition in September despite initial rejection by the secretary of state. Multiple U.S. Supreme Court actions left the 2022 map in place for the current election. Trader sentiment favoring rejection reflects the map’s partisan origins as a mid-decade redraw, substantial signature collection by opponents, active campaign efforts highlighting gerrymandering concerns, and Missouri’s precedent of voters blocking similar legislative redistricting plans through referendum.