Across all 5,807 state legislative seats up for election in 2024, 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 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.
Here’s what we know about average margins in those races:
- Major-party candidates won 803 seats by margins of 10 percentage points or fewer; 409 of those seats were won by Democrats and 394 by Republicans.
- The average margin of victory was 25.1% for Democrats and 28.9% for Republicans.
- The chamber with the smallest average margin of victory in 2024 was the New Hampshire House of Representatives (9.4%), followed by the Nevada State Senate (10.2%) and the Vermont State Senate (10.2%).
That’s compared to 2022, when the 6,278 seats up for election had an average margin of victory of 27.7%. That year, major-party candidates won 875 seats by margins of 10 percentage points or fewer—471 of those seats were won by Democrats and 404 by Republicans.
The average margin of victory across all upper chambers was 29.2%, and the average margin of victory across all lower chambers was 27.9%.
Close state legislative races
In 2024, there were 810 races decided by 10 percentage points or fewer, including 47 under 0.5 percentage points. There were 882 races decided by 10 percentage points or fewer in 2022, with 65 decided by 0.5 percentage points or fewer. The map below shows the percentage of races in each state decided by margins of 10% or less.
Sixty-four (1.1%) of the 2024 state legislative races were decided by fewer than 100 votes.
In 2022, 103 (1.64%) of the 6,278 state legislative races were decided by fewer than 100 votes. In 2020, 30 (0.5%) of the 5,875 state legislative races were decided by fewer than 100 votes.
The New Hampshire House of Representatives had 22 races decided by fewer than 100 votes—more than any other chamber. The Maine House of Representatives and Vermont House of Representatives each had nine races decided by fewer than 100 votes—the second-highest number after the New Hampshire House.
The map below shows the states where state legislative races decided by fewer than 100 votes took place.
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