Which states show the most effective Democratic versus Republican gerrymanders in 2024 elections?
Executive summary
Maps used in 2024 produced clear, state-by-state advantages: the Brennan Center estimates Republicans gained about 16 extra House seats nationwide versus “fair” maps, with Texas and Florida among the biggest single‑state sources of that GOP edge (Brennan Center; TPR) [1] [2]. Independent trackers (Princeton/PlanScore/Duke, etc.) and news outlets identify North Carolina, Texas, Florida, and Ohio as leading examples of effective Republican gerrymanders in 2024, while California and Illinois are frequently cited as the most effective Democratic gerrymanders [3] [4] [5] [6].
1. The national picture: Republicans’ estimated 16‑seat structural edge
Post‑2024 analyses found a sizable national tilt created by maps: the Brennan Center’s modeling puts Republican advantage at roughly +16 House seats compared with maps meeting the Freedom to Vote Act’s anti‑gerrymandering standards, and notes that much of that advantage is concentrated in a handful of states [1] [4]. FactCheck and other analysts emphasize that methodological choices matter—different studies reach different magnitudes, but most agree Republicans benefited overall [7] [4].
2. Texas and Florida: Big states, big payoff for map‑makers
Multiple reports single out Texas and Florida as places where Republican map‑making delivered dozens of safe GOP seats. The Brennan Center and regional studies show Texas yielded several extra GOP seats compared with “fair” alternatives; one Texas study estimated a five‑seat GOP advantage there alone, and combined Texas+Florida accounted for roughly 10 extra safe GOP seats relative to a Freedom to Vote Act model [2] [1]. The Guardian and The Atlantic also highlight Texas as a high‑impact case of partisan map engineering [8] [9].
3. North Carolina: a textbook mid‑decade gerrymander that flipped seats
North Carolina’s 2024 map was repeatedly cited as a striking example: courts had ordered remedial maps, then state actors replaced them with GOP‑drawn lines that the Brennan Center and Duke/Princeton analyses say shifted roughly three Democratic seats to Republican control in 2024, producing delegations as skewed as 11‑3 in some projections [1] [3] [10]. These analyses show how state supreme court changes and legislative control translated directly into seat flips [4] [10].
4. Ohio and other battlegrounds: litigation, commissions, and mixed outcomes
Ohio’s maps prompted repeated court action and ballot fights; reporting shows courts threw out multiple versions and voters considered reforms [11]. The net practical effect in 2024 was a mix: some maps were struck down, some held, and overall competitiveness fell—only about 1 in 10 districts nationwide were competitive, per Brennan Center analysis [12]. That mix means Ohio is a key example of contested, opportunistic line‑drawing rather than a single uncontested “winner” [12] [11].
5. Democratic gerrymanders: California, Illinois and where Democrats packed advantage
Scholars and news outlets identify several states where Democrats drew maps producing very lopsided Democratic delegations. California’s maps have been described as effectively excluding many Republican voters from representation and in one analysis would leave 92% of districts leaning Democratic under a proposed map (The Fulcrum; World Population Review/Princeton citations) [5] [6]. Illinois is likewise named as an example of an aggressive Democratic map at the congressional level [5].
6. How analysts measure “most effective” — the politics of metrics
Different organizations use different metrics: Brennan Center compares actual maps to simulated “Freedom to Vote Act” compliant maps and calculates net seat swings; Princeton’s Gerrymandering Project and PlanScore use ensemble simulations and metrics like efficiency gap, mean‑median and declination; Duke research creates simulated vote swings to test map durability [1] [13] [14] [10]. Method choice produces different state rankings; that explains why some outlets emphasize Texas/North Carolina while others flag California/Illinois [1] [14].
7. Competing interpretations and limits of post‑2024 claims
Some analysts say gerrymandering was decisive in producing an overall GOP advantage; others and some statisticians told FactCheck that partisan redistricting had limited net effect in 2024 depending on methods [7] [4]. Available sources do not mention a single universally accepted “top five” list — rankings vary with methodology and the counterfactual used [7] [14]. That methodological disagreement is itself a central story of the 2024 redistricting debates.
8. What to watch next: mid‑decade maps and legal fights
Reporting through 2025 documents continued mid‑decade redraw efforts (Texas special sessions, Prop 50 in California, new maps in multiple states) and fresh court orders reversing or pausing maps, meaning the roster of “most effective” gerrymanders remains fluid [8] [15] [5]. Democracy Docket, The New York Times and Brookings trace these follow‑on moves as the battlefield for control of future Congresses [16] [15] [17].
Limitations and sources: This analysis synthesizes the Brennan Center, Princeton/Duke projects, The Guardian, TPR, The Fulcrum, PlanScore and reporting summarized above; differing metrics and counterfactuals produce differing state rankings, and available sources do not offer one definitive, universally accepted ordering of “most effective” gerrymanders [1] [14] [7].