The Missouri Supreme Court unanimously ruled on September 3, 2026, that a new Republican-backed congressional map cannot be used for the November general election. The court ordered election officials to use the congressional boundaries adopted in 2022 and placed a referendum on the November ballot that will allow Missouri voters to decide whether the new map should ultimately take effect.

Introduction

Missouri's midterm elections voting boundaries will revert to the state's 2022 congressional map for the November 2026 general election after the Missouri Supreme Court unanimously blocked a new Republican-drawn map from being used.

The ruling, issued September 3, came after a legal fight over a referendum petition challenging the congressional redistricting plan passed by Missouri's Republican-led Legislature. The Supreme Court concluded that the referendum petition was legal, sufficient and timely under the Missouri Constitution.

The decision means that the new map, which was already used during Missouri's August 4 congressional primaries, cannot be used for the November general election unless Missouri voters approve it in the referendum.

The ruling is politically significant because Republicans had designed the new boundaries with the goal of improving their chances of gaining another U.S. House seat. It also creates an unusual situation in which candidates competed in the primary under one set of congressional boundaries but will face the general election under another.

What Happened?

The dispute centers on House Bill 1, the congressional redistricting plan approved by Missouri lawmakers in 2025.

The new map was part of a broader effort to redraw congressional districts in the middle of the decade. In Missouri, the Republican-led Legislature adopted boundaries that significantly changed several districts, including the Kansas City-area 5th Congressional District held by Democratic Rep. Emanuel Cleaver.

Opponents of the map organized a referendum effort through the group People Not Politicians. The campaign collected more than 300,000 signatures seeking to put the new redistricting law before voters.

Missouri Secretary of State Denny Hoskins rejected the referendum petition shortly before the August primary, arguing that the Missouri Constitution did not permit a referendum on congressional redistricting.

The dispute went to court.

On September 3, the Missouri Supreme Court reversed the lower court's decision and ruled that the referendum petition was valid.

More importantly for November's election, the Supreme Court ordered that the 2022 congressional map remain in force for the 2026 general election.

Key Details

The Supreme Court's ruling establishes several important points:

• The court ruled unanimously in favor of the referendum.
• The 2025 congressional redistricting plan cannot be used for the November 2026 general election.
• Missouri's 2022 congressional boundaries will govern the November election.
• Voters will see a referendum concerning the new map on the November ballot.
• The new map could take effect if voters approve it.
• The August 4 primary was conducted using the newer boundaries.
• The ruling does not change the results of the August primary.
• Republicans have indicated they intend to seek review by the U.S. Supreme Court.

The Missouri Supreme Court specifically ordered the secretary of state to take the necessary steps to put the referendum on the November ballot before September 8.

Background: Why Missouri Redrew Its Congressional Map

Congressional redistricting normally takes place after the decennial U.S. census. Missouri's existing congressional districts were drawn following the 2020 census and have been used for subsequent elections.

The 2025 legislation represented an unusual mid-decade attempt to change those boundaries before the next census.

The Republican effort was politically important because Missouri's congressional delegation and the national balance of power in the U.S. House were at stake.

The new map particularly affected the 5th Congressional District. The revised boundaries were intended to make the district more favorable to Republicans and potentially help the GOP gain another seat in Missouri's congressional delegation.

The dispute therefore became part of a broader national battle over mid-decade redistricting.

Why the Referendum Became the Central Legal Issue

The Missouri Supreme Court focused heavily on the language of the state Constitution.

The court concluded that Article III, Section 49 authorizes referendums concerning "any act of the general assembly" and contains no specific exception for congressional redistricting.

Because the Constitution did not expressly exclude congressional maps from the referendum process, the court determined that the petition could legally challenge the 2025 redistricting law.

The court also determined that the referendum petition was submitted in time and met the required signature threshold.

That meant the redistricting legislation was subject to the referendum process rather than taking effect for the November election.

What Officials and Organizations Said

Missouri Attorney General Catherine Hanaway criticized the ruling and said her office would seek relief from the U.S. Supreme Court.

Hanaway argued that the decision created serious constitutional problems because the map had already been used for the primary election.

Republican officials have also objected to switching congressional boundaries between the primary and general elections, arguing that the change could create confusion for candidates and voters.

Supporters of the referendum took the opposite view.

People Not Politicians, the group behind the referendum effort, welcomed the ruling as a confirmation of Missouri voters' ability to challenge legislation through the referendum process.

The competing reactions highlight the two major issues in the case: the constitutional authority to challenge the map and the practical consequences of changing congressional boundaries after a primary.

What Does the Ruling Mean for Missouri Voters?

For voters, the most immediate consequence is that the congressional district associated with their November ballot may not be the same district used during the August primary.

The Supreme Court's ruling makes the 2022 map the operative congressional map for the November 2026 general election.

That means voters should not assume that the district boundaries they saw during the primary will remain in place.

The ruling does not cancel the August primary results. Candidates who won their party nominations remain the nominees from that election, but the districts in which they compete during the general election may be different.

This could be particularly important in districts that were substantially altered by the 2025 map.

Why This Matters

The case has implications beyond a single congressional election.

First, it demonstrates the potential power of voter-initiated referendums in Missouri. The Supreme Court's interpretation means congressional redistricting legislation can be subjected to a referendum when the constitutional requirements are met.

Second, the ruling could affect the national political fight over congressional redistricting.

Republicans and Democrats have increasingly turned to mid-decade redistricting as both parties seek to influence the makeup of the U.S. House before the next census.

Missouri's case is particularly notable because the court blocked the new map after it had already been used for the primary election. Reuters described the ruling as a setback for Republicans and former President Donald Trump's effort to reshape congressional districts in their favor.

Third, the decision creates an unusual electoral timeline: Missouri voters used the new map in August but will use the older map in November unless the legal situation changes.

What Happens Next?

The immediate next step is the November referendum.

The Missouri Supreme Court ordered Secretary of State Denny Hoskins to place the referendum on the November 2026 general election ballot. The court's opinion states that the new map will not take effect unless voters approve it.

There is also a federal legal challenge ahead.

Attorney General Catherine Hanaway has said Missouri will seek U.S. Supreme Court review. That means the legal dispute may not be completely finished, even though the Missouri Supreme Court has established the boundaries that should be used for the November election under its current order.

For now, the key confirmed position is straightforward: the 2022 congressional map remains in effect for Missouri's November 2026 general election unless the legal situation changes or voters approve the new map.

FAQs

What are Missouri's midterm elections voting boundaries for November 2026?

The Missouri Supreme Court ruled that the 2022 congressional district boundaries must be used for the November 2026 general election. The newer 2025 map cannot be used unless it is approved through the referendum process.

Why did the Missouri Supreme Court block the new GOP map?

The court determined that a referendum petition challenging the 2025 congressional redistricting law was legally valid. Because the map was subject to referendum, the court ruled that the new boundaries could not be implemented for the November election.

Was the new map used in Missouri's primary election?

Yes. Missouri held its congressional primary on August 4, 2026, using the new congressional boundaries. The Supreme Court's September ruling did not invalidate the primary results.

Will Missouri voters vote on the new congressional map?

Yes. The Supreme Court ordered the referendum concerning the 2025 redistricting plan to appear on the November 2026 general election ballot.

What happens if voters approve the new map?

The Supreme Court's opinion states that the 2025 redistricting plan will take effect if voters approve it. The court also specified that the plan would take effect 30 days after voter approval.

Does the ruling change the August primary results?

No. The ruling does not undo the August primary. Candidates who won their party nominations remain connected to those results, although the congressional boundaries used for the November election will be different.

Could the U.S. Supreme Court change the situation?

Possibly. Missouri Attorney General Catherine Hanaway has indicated that the state will seek review by the U.S. Supreme Court. Any further federal court action could affect the legal status of the map, but the Missouri Supreme Court's current ruling requires the 2022 map to be used for the November general election.

Why is the Missouri redistricting case nationally significant?

The case is part of a broader national debate over mid-decade congressional redistricting. The Missouri ruling is particularly significant because it allows voters to decide the fate of a congressional map through a referendum and prevents the new map from being used in the state's November election unless approved.

Sources

Primary source: Supreme Court of Missouri, Richard von Glahn v. Denny Hoskins, Case No. SC101805 — official September 3, 2026 opinion.

Additional reporting: Reuters and Associated Press reporting on the Missouri Supreme Court ruling and its political and electoral consequences.

Additional state-level reporting: Missouri Independent's coverage of the referendum and congressional map ruling.

Publication date: September 4, 2026.