The Missouri Supreme Court has blocked the state’s mid-decade congressional map, ruling that it cannot be used in the November elections. The map had been drawn to give the governing party an additional seat, part of a wave of redistricting outside the normal ten-year cycle.

The ruling matters beyond Missouri because it was decided on state constitutional grounds — the one route in American redistricting litigation that the federal courts have largely left open.

Why state courts are where this happens now

In Rucho v. Common Cause (2019), the US Supreme Court held that claims of partisan gerrymandering present political questions that federal courts cannot resolve. The decision closed the federal door while explicitly noting that state constitutions and state courts remained available.

Litigants took the invitation. State constitutions often contain provisions with no federal analogue — free and equal elections clauses, explicit requirements about county boundaries or compactness, or rules about when redistricting may occur at all. Those provisions are what mid-decade maps have repeatedly run into.

There is a limit to how far this generalises. State supreme court judges are elected or politically appointed in most states, and rulings have not fallen along consistent partisan lines. A win in one state’s courts predicts very little about the next.

Timing is the substance

A ruling that a map cannot be used in November is a different thing from a ruling that a map is unlawful. Courts weighing election cases apply a strong preference against changing the rules close to an election, on the reasoning that late changes confuse voters and administrators. That principle usually protects whichever map is already in place — which, in a mid-decade redistricting fight, means it can favour either side depending on when the challenge is heard.

Here it has cut against the new map. The practical effect is that the previous boundaries govern this election, and the legal question of whether the new ones are permissible may still be resolved afterwards.

The arms race this belongs to

Mid-decade redistricting has become a mutual escalation: states controlled by one party redraw maps to gain seats, states controlled by the other respond, and each side describes its own move as a correction and the other’s as a subversion of democracy.

The defence offered is generally that nothing in law prohibits redrawing districts between censuses, that legislatures are the constitutionally designated body for the task, and that a party which refuses to use a lawful tool its opponents are using simply loses seats. The case against is that districts redrawn for partisan advantage let representatives select voters, and that maps changed between elections make representation contingent on which party held a legislature in a given year.

Neither argument is going to be settled by a court. What state courts can do — and what Missouri’s has just done — is decide whether a particular map complies with a particular state constitution, one election at a time.

Sources

• Missouri Supreme Court ruling on the state’s congressional map, September 2026
• Rucho v. Common Cause, 588 US 684 (2019)
• Reporting on mid-decade redistricting across US states, 2026