Margin of victory analysis for the 2025 state legislative elections
In November 2025, two of the nation's 99 state legislative chambers held regularly-scheduled elections for 180 seats, meaning that 2.4% of all state legislative seats were up for election.
Democrats expanded their majorities in the Virginia House of Delegates and New Jersey General Assembly. As a result of the states' legislative and gubernatorial elections, Democrats gained a trifecta in Virginia and maintained a trifecta in New Jersey.
Across all 180 seats up for election, the average margin of victory was 24.7%. 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.
2025's average margin of victory of 24.7% was the second-lowest in odd-year elections since 2019, and down from 28.7% in 2023. The average state legislative margin of victory was 23.6% in 2021 and 26.0% in 2019. The average was 27.3% in 2024, 27.7% in 2022, and 27.0% in 2020.
Of the 180 state legislative seats up for election in 2025, 20.5% (37 seats) were decided by a margin of victory of 10% or less. This was the second-highest among odd-year election cycles since 2019. The share of seats decided by a margin of victory of 10% or less was 9.7% in 2023, 20.9% in 2021, and 10.6% in 2019.
Of the 37 state legislative races decided by a margin of victory of 10% or less in 2025, Democrats won 22 (59.5%) and Republicans won 15 (40.5%). Democrats won 35.7% of races with a margin of victory of 10% or less in 2023, and Republicans won 64.3%.
On this page, you will find an overview of average margins of victory by chambers and size of the margin, including:
- Upper chamber average margins of victory
- Lower chamber average margins of victory
- Election results by chamber
- Races decided by 10% or less
- Races decided by 0.5% or less
- Historical margins of victory
To learn more about margins of victory in the previous odd-year state legislative elections (2023), click here. To read our margin of victory analysis for U.S. Congress in the previous even-year elections (2024), click here.
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
No upper state legislative chambers held regular elections in 2025.
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.
| Chamber | Seats up for election | Average margin of victory |
|---|---|---|
| New Jersey General Assembly | 80 | 12.5% |
| Virginia House of Delegates | 100 | 30.2% |
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 2025. A darker shade of red or blue indicates a larger margin for that party.
The table below displays how many seats were up for election in each chamber and how many seats each party won. It also includes a breakdown of how many seats Democrats and Republicans won by 10% or less and without opposition in each chamber, as well as the average margin of victory for each party. Click on a particular header to sort the table.
| Chamber | Seats up for election |  Seats won by Democrats | Seats won by Democrats by margins of 10% or less | Seats won by unopposed Democrats | Average margin of victory for Democrats |  Seats won by Republicans | Seats won by Republicans by margins of 10% or less | Seats won by unopposed Republicans | Average margin of victory for Republicans |  Seats won by independent and minor party candidates |
|---|---|---|---|---|---|---|---|---|---|---|
| New Jersey General Assembly | 80 | 29 | 10 | 2 | 15.2% | 11 | 8 | 0 | 5.9% | 0 |
| Virginia House of Delegates | 100 | 64 | 12 | 15 | 32.6% | 36 | 7 | 0 | 26.9% | 0 |
| Totals | 180 | 93 | 22 | 17 | 26.4% | 47 | 15 | 0 | 22.0% | 0 |
State legislative races decided by 10% or less
In 2025, there were 37 races decided by margins of 10% or less. The map below shows the percentage of races in each state decided by margins of 10% or less.
State legislative races decided by 0.5% or less
In 2025, there were two races decided by margins of 0.5% or smaller.
| District | Winner | Runner-up | Margin (%) | Margin (number of votes) |
|---|---|---|---|---|
| New Jersey General Assembly District 2 | Maureen Rowan | Joanne Famularo | 0.12% | 193 |
| New Jersey General Assembly District 25 | Aura Kenny Dunn | Christian Barranco | 0.49% | 963 |
Historical margins of victory
The table below shows the number of seats up for election and the average margin of victory for all regularly-scheduled state legislative elections since 2018.
| Year | Seats up for election | Average margin of victory |
|---|---|---|
| 2025 | 180 | 24.7% |
| 2024 | 5,807 | 27.3% |
| 2023 | 578 | 28.7% |
| 2022 | 6,278 | 27.7% |
| 2021 | 220 | 23.6% |
| 2020 | 5,875 | 27.0% |
| 2019 | 538 | 26.0% |
| 2018 | 6,073 | 25.8% |
See also
- State legislative elections, 2025
- State legislative special elections, 2025
- Ballotpedia's Election Analysis Hub, 2025
Footnotes
