Missouri voters face Proposition A on November 3, 2026, a veto referendum on House Bill 1, the congressional map enacted in a 2025 special session and signed by Governor Mike Kehoe. The measure would uphold new boundaries drawn to create a 7-1 Republican advantage, primarily by splitting Kansas City across districts. The Missouri Supreme Court’s unanimous September 3 ruling validated the citizen petition after more than 300,000 signatures were submitted, placed the question on the ballot, and kept the prior 2022 map in effect for the general election pending the outcome. Trader consensus slightly favoring rejection reflects the map’s origin as a mid-decade partisan redraw, the organized opposition campaign, and Missouri’s precedent of using referendums to check legislative redistricting actions. Appeals to federal courts continue but have not changed the November vote.