Missouri congressional map dispute heads to Supreme Court for third time

The legal battle over Missouri's congressional map is likely headed to the U.S. Supreme Court for a third time in as many weeks, as federal judges continue to debate which districts should be used for the upcoming November elections. The U.S. Supreme Court has so far allowed a Missouri Supreme Court decision to stand, which ordered the state to use the congressional districts from the 2022 elections.

A resolution from the nation's highest court could bring an end to the dispute, providing clarity for over a million voters who have been moved between districts, causing confusion about their ballots.

The Missouri Supreme Court ruled on September 3 that new congressional districts, passed by the Republican-led state Legislature a year prior and supported by former President Donald Trump, could not be implemented unless approved by voters through a referendum. The court cited the state constitution, which allows for statewide referendums on legislative acts, stipulating that such measures only take effect upon voter approval.

Opponents of the new map submitted thousands of signatures for a referendum petition in December. Missouri Secretary of State Denny Hoskins, a Republican, rejected the petition on August 4, the same day primaries were held using the newly drawn districts. Hoskins asserted that congressional redistricting maps are not subject to referendums. However, the state Supreme Court disagreed, ruling that the referendum petition had prevented the new map from taking effect retroactively to December. This meant the August primary was conducted under districts not officially enacted into law. The court concluded that the November election must proceed using the only districts still valid under state law: a map established in 2022 following the most recent census.

U.S. Supreme Court Justice Brett Kavanaugh, who oversees cases from Missouri, allowed the state Supreme Court's decision to remain in effect on September 8.

More recently, a three-judge panel of the 8th U.S. Circuit Court of Appeals ruled that the U.S. Constitution prohibits changing congressional districts between primary and general elections. While the Constitution does not explicitly state this, the judges pointed to a provision requiring U.S. House members to be elected every two years and cited previous court rulings that primaries can be an integral part of a state's general election laws. They noted that shifting over a million voters—approximately one-quarter of the state's electorate—between districts would deny these voters their constitutional right to choose their representatives, as they would not have participated in the primary election for the candidates appearing on their general election ballots.

The appeals panel instructed U.S. District Judge Stephen Clark to issue an order preventing Missouri from using any districts other than those used in the August primary. Judge Clark promptly complied. Clark had previously issued a similar temporary order on September 8, which was placed on hold by the U.S. Supreme Court two days later. Opponents of the new map intend to ask the Supreme Court to block this latest order as well.

Throughout this protracted legal process, both proponents and opponents of the new congressional map have raised arguments about the timing of any potential changes. The U.S. Supreme Court's "Purcell principle," established in a 2006 case, suggests that judges should avoid altering election rules close to an election. Currently, absentee voting is underway in Missouri using the 2022 congressional districts, and opponents argue it is too late to switch back to the newer map. Conversely, supporters of the new districts also invoke the Purcell principle, arguing that it is too late to abandon the districts used in the August primary. The appeals panel, however, sided with the argument that using the 2022 map would cause the least confusion for voters.