Purcell v. Gonzalez
2006 Supreme Court ruling that warned federal courts against changing election rules near polling day.
On 21 September 2026 the 8th Circuit ordered Missouri onto its 2025 congressional map weeks before polling day, an order Law Dork's Chris Geidner said inverted the Purcell principle against late changes to election rules.
Last refreshed: 18 October 2026
Timeline for Purcell v. Gonzalez
Mentioned in: Supreme Court keeps parties' ad discount
US Midterms 2026Mentioned in: 8th Circuit puts Missouri on 2025 map
US Midterms 2026Mentioned in: Shadow docket shields Alabama map for 2026
US Midterms 2026Mentioned in: SCOTUS orders Callais into immediate effect
US Midterms 2026Background
Purcell v. Gonzalez, 549 U.S. 1 (2006), is an unsigned (per curiam) Supreme Court of the United States ruling of 20 October 2006. It is the source of the Purcell principle: federal courts should hesitate to change election rules close to an election.
The case concerned Proposition 200, which Arizona voters approved in 2004. It required proof of citizenship to register and identification at the polls. A two-judge Ninth Circuit motions panel blocked the law weeks before the 2006 election without giving reasons. the Supreme Court vacated that order, warning that "court orders affecting elections, especially conflicting orders, can themselves result in voter confusion and consequent incentive to remain away from the polls", a risk that grows as an election draws closer.
Litigants invoke it in most late election fights. Missouri cited it in its map application in September 2026. the Court's October 2026 stay keeping the FCC's party ad-rate guidance in force also halted a late lower-court order.
A late map order inverted the principle
Missouri invoked Purcell first. Its 4 September 2026 application to Justice Brett Kavanaugh cited the principle and counted 1.2 million votes already cast under the suspended districts at the 4 August primary.
Three 8th Circuit judges sided with HB 1, the 2025 lines, on 21 September, holding that a November vote under it would confuse voters less than one under the 2022 map. Chris Geidner of Law Dork wrote that the panel had inverted Purcell, which warns federal courts off changing election rules close to a vote. The order came days after Missouri had mailed overseas ballots on the 2022 map. the Court paused it until 28 September, and the challengers turned to Kavanaugh.
Purcell now shields contested maps
When the Supreme Court put Louisiana v. Callais into immediate effect on 4 May 2026, The Heritage Foundation's Hans von Spakovsky defended the speed by citing Purcell, reading the order as routine management of a live election calendar.
The principle then cut for a map. On 2 June the Court's six Conservative justices issued an unsigned stay reinstating Alabama's post-Callais map seven days after a district court blocked it. Critics at the Brennan Center argue Purcell was framed to protect voters from destabilising late injunctions, not to preserve a contested map until an appeal can no longer matter.
What is the Purcell principle?
What was Purcell v. Gonzalez about?
When was Purcell v. Gonzalez decided?
Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Updated 18 October 2026. Editorial standards.