Mid-decade redistricting, explained: which states will vote under new House maps on Nov. 3, and what the Callais ruling changed

States usually redraw House districts once a decade, after the census. This cycle has been different. Since summer 2025, the National Conference of State Legislatures counts 10 states that have changed their congressional maps, which it calls a pace not seen since the 1800s. Not all of those maps will be used on November 3.

New maps in use for 2026 (by our count from NCSL's tracker, updated Sept. 11)

• Alabama: back to its 2023 map, which the Supreme Court allowed to take effect on June 2.
• California: map adopted through Proposition 50, which voters approved Nov. 4, 2025.
• Florida: map enacted May 4, 2026. A state-court challenge is pending.
• Louisiana: map enacted May 29, 2026. Congressional primaries were moved to Nov. 3, with general elections on Dec. 12.
• North Carolina: map enacted Oct. 22, 2025.
• Ohio: map adopted Oct. 31, 2025, by the state's backup redistricting commission with bipartisan agreement.
• Tennessee: map adopted May 7, 2026, after lawmakers repealed a state ban on mid-decade redistricting.
• Texas: map enacted in August 2025. The Supreme Court stayed a lower-court injunction on Dec. 4, 2025.
• Utah: map adopted by court order Nov. 10, 2025.

Missouri is the 10th state. Its 2025 map is on hold until voters decide a referendum on it in November, so the 2022 map is in effect. NCSL says Missouri held its August primaries under the 2025 map, and that primary winners are expected to run in the same-numbered district, with its shape set by the 2022 map. That is why we count nine maps, not 10, as in use this fall.

Not changing for 2026: Virginia's Supreme Court struck down its new map on May 8, so the 2021 map stays. Maryland voters will decide a constitutional amendment (HB 2100) on Nov. 3 that NCSL says is widely understood to set up redistricting later. Georgia's and Indiana's legislatures declined to redraw.

What Louisiana v. Callais decided

On April 29, 2026, in Louisiana v. Callais, the Supreme Court ruled 6-3 that Louisiana's SB8 map, which added a second majority-Black district, was an unconstitutional racial gerrymander. The Court held that the Voting Rights Act didn't require that district, so race couldn't justify drawing it.

The majority. Justice Samuel Alito, writing for the Court, said complying with Section 2 of the Voting Rights Act can justify considering race, but only when Section 2 is read correctly. Under that reading, Section 2 imposes liability only when the evidence supports a strong inference that a state intentionally drew districts to give minority voters less opportunity because of their race. The opinion says Section 2 doesn't stop states from drawing lines on nonracial grounds, partisan advantage included. It keeps the decades-old Thornburg v. Gingles test but updates it. Among its reasons, the majority cites social change in the South, the rise of a two-party system in which race and party preference often correlate, and the Court's earlier holding that partisan gerrymandering claims can't be heard in federal court, which it says creates an incentive to bring them as Section 2 claims.

The dissent. Justice Elena Kagan, joined by Justices Sonia Sotomayor and Ketanji Brown Jackson, wrote that when courts had required proof of discriminatory intent, Congress amended Section 2 so that it "turned solely on discriminatory effects." In her view, splitting a cohesive minority community across districts so it "loses all its electoral influence," known as "cracking," is "racial vote dilution in its most classic form," and Section 2 made the practice illegal. She also described the Voting Rights Act as having been, in her words, subject to the majority's "now-completed demolition."

Why it matters beyond Louisiana

NCSL reports that after Callais, the Supreme Court lifted an order that had barred Alabama from redrawing until after 2030 (May 11). A federal court then ruled Alabama's 2023 map violated Section 2 under the new standard, and on June 2 the Supreme Court reversed that ruling, allowing the map to take effect. NCSL calls that the first time federal courts applied the Callais test. NCSL's tracker also reports that, after Callais, Mississippi's governor cancelled a special session on redistricting and the Supreme Court reversed a 2024 order for Mississippi to redraw its state legislative districts.

Sources

• Supreme Court, Louisiana v. Callais, No. 24-109 (PDF)
• NCSL, Changing the Maps: Tracking Mid-Decade Redistricting

Drafted with AI assistance from primary sources. Written and edited by The Whole Read newsroom under Monsaur Othman's editorial standards. Read how we use AI, our editorial policy and our corrections policy.