Margin of victory analysis for the 2024 state legislative elections
On November 5, 2024, 85 of the nation's 99 state legislative chambers held regularly-scheduled elections for 5,807 seats, meaning that 79.0% of all state legislative seats were up for election.
Two state legislative chambers, the Michigan and Minnesota state Houses, changed party control following the 2024 general election. Republicans won control of the Michigan House from Democrats, and won a tie in the Minnesota House. Democrats lost trifecta control in both states, resulting in divided governments.
Across all 5,807 seats up for election, the average margin of victory was 27.3%. An electoral margin of victory (MOV) is the difference between the share of votes cast for the winning candidate and the second-place candidate in an election. Only races with more than one candidate were included in this average.
On this page, you will find an overview of average margins of victory by chamber, a detailed breakdown of each legislative chamber's margins of victory, and a closer look at the races decided by margins of 0.5% or smaller.
To learn more about margins of victory in the previous even-year state legislative elections (2022), click here. That year, across the 6,278 seats up for election, the average margin of victory was 27.7%. Major-party candidates won 875 seats by margins of 10% or less—471 of those seats were won by Democrats and 404 by Republicans.
Margin of victory
The margin of victory is the difference between the vote share received by a winning candidate and the runner-up. For example, if Candidate A wins an election with 55 percent of the vote and Candidate B, the second-place finisher, wins 45 percent of the vote, the winner's margin of victory is 10 percent. In chambers with multimember districts, the margin of victory is calculated as the difference between the winning candidate with the fewest votes and the losing candidate with the most votes. Margins of victory can be used to measure electoral competitiveness, political party or candidate strength, and, indirectly, the popularity of a particular policy or set of policies.
Upper chamber average margins of victory
The table below shows the number of seats up for election and the average margin of victory in each state legislative upper chamber.
Lower chamber average margins of victory
The table below shows the number of seats up for election and the average margin of victory in each state legislative lower chamber.
Election results by chamber
The chart below displays the breakdown of races by the winner's partisan affiliation and margin of victory for each state legislative chamber with single-member districts which held elections in 2024. A darker shade of red or blue indicates a larger margin for that party.
See also
- State legislative elections, 2024
- State legislative special elections, 2024
- Trends in the margins of victory for incumbents of three or more terms, 2018-2024
Footnotes
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