Redistricting Wars Barely Backfire on Republicans: The Word on Their 2026 House Map Gains

A modest Republican advantage

Republicans began redrawing congressional districts in summer 2025, seeking enough seats to improve their chances of keeping control of the House in the 2026 midterms. The preliminary estimate finds that the changes added between four and seven Republican seats. The effort did not deliver the hoped-for gains, but the analysis says it did not cost Republicans seats overall.

North Carolina stands apart

North Carolina is the one state where the Republican redistricting effort appears to have backfired, though only narrowly. In other states, Republicans either benefited or the new maps had no effect on the outcome. The analysis also notes Republicans already had a substantial structural advantage in the House from gerrymandering.

How the seat estimates work

Researchers compared the number of seats each party won in 2026 with estimates of how the same votes would have translated under 2024 district boundaries or computer-simulated maps. The election results came from The New York Times, and simulated maps came from Harvard’s ALARM Project or its redistricting algorithms.

For races not called at publication, the analysis used ranges based on outstanding votes. In Louisiana, it combined Democratic and Republican votes in the Fifth and Sixth Districts to project the winners of December runoffs.

To recalculate results across different district boundaries, researchers used county and district votes, or precinct votes where available. When a county was split by another map, votes were apportioned according to the location of each party’s voters in 2024; if a race lacked a Democratic or Republican candidate, statewide vote changes since 2024 were used.

Limits of the comparison

For simulated maps, researchers averaged results across 5,000 plans, producing fractional seat totals. The simulations averaged 23.3 Democratic seats. Race-based redistricting constraints were removed to reflect the Supreme Court’s decision in Louisiana v. Callais.