Missouri Asks the Supreme Court to Extend a Federal Election Doctrine to State Courts

Missouri election officials have until 5 p.m. Central time on September 28 to learn which congressional map governs the state's November election. One version, drawn by Republican state lawmakers in 2025 and known as House Bill 1, was already used to run the August primary and is expected to give the GOP an additional U.S. House seat centered on Kansas City. The other, from 2022, is the map a unanimous Missouri Supreme Court ordered restored on September 3. The U.S. Court of Appeals for the Eighth Circuit put House Bill 1 back into effect on September 21, and the fight is now before the U.S. Supreme Court for the third time since the map was drawn.

How the appeals court used Purcell to justify a late map switch

The Purcell principle usually cuts the other way. It takes its name from Purcell v. Gonzalez, the Supreme Court's 2006 ruling on an Arizona voter ID law, and it tells federal courts to leave election rules alone once voting is close, on the theory that late changes confuse voters and administrators. The Eighth Circuit used that same logic on September 21 to justify swapping maps three weeks before the ballot deadline, writing that using House Bill 1 would lead to the least amount of confusion for voters subjected to a string of changes that month.

Candidates had already filed to run under House Bill 1's district lines, and more than a million Missourians voted under it in the August primary. When the Missouri Supreme Court ruled unanimously on September 3 that a referendum petition against the map was valid, it ordered Secretary of State Denny Hoskins to use the 2022 map instead. The Eighth Circuit's September 21 ruling reversed that outcome, holding that switching back again so close to the election would itself create the kind of disorder the Constitution's requirement that House members be chosen under settled rules is meant to prevent.

The bigger ask: applying Purcell to state courts

Missouri's argument for keeping House Bill 1 in place is not new; the Eighth Circuit already accepted a version of it. What is new is a second, broader request filed alongside that fight: Missouri and 20 other Republican-led states are asking the U.S. Supreme Court to rule that Purcell also limits state courts interpreting their own state constitutions, not only federal courts changing federal election rules. That would be an expansion. The doctrine has applied only to federal courts until now, and Missouri's own filing does not pretend otherwise.

“Admittedly, this Court has not addressed whether the Purcell principle can ever independently justify a state court's last-minute alteration to federal election rules.”

Richard von Glahn, executive director of People Not Politicians, the group that organized the referendum against House Bill 1, is asking the Supreme Court to block the Eighth Circuit's order instead. His side argues the confusion Missouri warns about is the state's own doing: lawmakers redrew the map once already in 2025, and defending that map now is not the same as leaving a settled system alone. Robert Onder, a Republican congressional nominee named as a respondent in the underlying suit and one of the direct beneficiaries of House Bill 1's new lines, is among those pressing the Eighth Circuit's ruling to stand.

The comparison worth drawing is to the independent state legislature theory, the argument that state legislatures have free rein over federal election rules with no check from state courts, which the Supreme Court rejected in Moore v. Harper in 2023. The legal mechanism here is different: this is a timing rule about when courts can act, not a claim about which branch has final say. But the practical effect would land in a similar place. Either theory ends with a state court unable to enforce its own constitution against a legislature's map once an election is underway.

A pattern, not a one-off filing

This is the third time in roughly seven months that a fight over this one map has reached the Supreme Court on an emergency basis. Justice Brett Kavanaugh, who handles emergency election appeals arising from the Eighth Circuit, paused a lower court order in the same case on September 10. Emergency, same-cycle trips to the Court over a single state's map are not unheard of, but three in one redistricting fight, before a single general election has even happened, is unusual even by the standard of a busy shadow docket.

Whatever the Court decides by September 28 settles only Missouri's ballots. The broader question, whether Purcell can be read to cover state courts enforcing their own constitutions, would not need a full written opinion to matter. A one-line order letting the Eighth Circuit's reasoning stand would tell other states, facing their own map fights this decade, how much room their own courts have to act once a primary has already happened.