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What were the closest congressional races by percentage in 2024?
Executive summary
The 2024 congressional cycle produced a large number of razor‑thin contests: multiple post‑election reviews report 80 House and Senate contests decided by 10 percentage points or fewer and 43 decided by five points or fewer, with Democrats prevailing in a majority of those tight contests [1]. The very narrowest margins were concentrated in California House races — most notably California’s 13th Congressional District decided by 187 votes (about 0.09 percent) — alongside single‑digit margins in several Senate and House fights that underscore how many seats were effectively decided by a handful of ballots [2] [3] [1].
1. Tight totals and partisan splits that shaped the map
Post‑election tallies compiled across reviews show 80 congressional races finished within a 10‑point spread, and 43 were closer than five points, indicating an unusually competitive cycle across both chambers [1]. Those compilations also quantify partisan outcomes among the close contests: Democrats won roughly 52 of the 80 races within ten points while Republicans captured about 28, a split that signals Democratic success in many competitive districts even where margins were small [1]. The same summaries note that in the universe of races decided by five points or fewer, Democrats retained an edge in wins, and several Senate contests were also decided within single digits, reinforcing that control of individual seats — not just statewide trends — determined much of the post‑election balance [1].
2. The absolute closest finishes: votes, percentages, and the headlines
Counting raw ballots and percentages, the tightest House outcome cited across reviews was California’s 13th District, decided by 187 votes — about 0.09 percent — making it the narrowest margin in the House in 2024 [2] [3]. Other ultra‑narrow House results included a 615‑vote margin in California’s 45th District and a sub‑800‑vote margin in a race won by Miller‑Meeks, each framed by coverage that compares these tallies to historical single‑digit and single‑vote congressional finishes [2] [3]. On the Senate side, sources identify Michigan’s Senate contest — Elissa Slotkin winning by roughly 0.34 percent — and Pennsylvania’s Senate race noted at about 0.22 percent in some reviews as among the closest statewide margins, illustrating that the closest fights were not limited to House districts but extended to high‑profile Senate battlegrounds [1].
3. Where the closest contests clustered and why analysts flagged them
Pre‑election battleground trackers and post‑election summaries converge on a set of tossup and near‑tossup districts that produced many of the closest outcomes: multiple California seats (including CA‑13, CA‑22, CA‑27), several Arizona and Colorado districts, and numerous Rust Belt and Sun Belt districts that were repeatedly rated competitive by the Cook Political Report and campaign trackers [4]. Analysts pointed to demographic change, redistricting shifts, and turnout differences as the proximate causes of tight margins; party programs such as DCCC “Red to Blue” targeting also focused resources on these districts, which likely narrowed margins further and turned many into coin‑flip finishes [5] [4].
4. Discrepancies in counts, reporting emphasis, and historical context
Different post‑election reviews emphasize slightly different metrics: one set reports totals of races within 10 and five points and party splits [1], while other coverage focuses on the handful of contests decided by tiny raw vote margins and places those in historical perspective, noting past congressional one‑vote decisions and other anomalies [2] [3]. These emphases reflect different editorial priorities — aggregate competitiveness versus drama of photo‑finishes — and both are factual; the aggregate counts show systemic competitiveness, and the close raw‑vote stories show how a few ballots can flip representation [1] [2].
5. What this means going forward: control, recounts, and public trust
The clustering of many races inside single‑digit margins and a handful decided by a few hundred votes had practical consequences: recounts and certification processes were required in several contests, and the narrow distributions shaped which party controlled chamber margins and committee leadership in the ensuing Congress [1] [3]. The data also implies heightened importance for voter mobilization, local turnout operations, and legal processes in future cycles because a small number of votes decided several seats in 2024. Observers and campaigns that produced pre‑election ratings — and those that ran targeted programs — will treat these close outcomes as validation of resource allocation strategies, while critics warn that such frequent narrow margins can intensify partisan disputes over procedures and count integrity [4] [5].