Ballotpedia releases 14th Annual State Legislative Competitiveness Report

Welcome to the Friday, Sept. 27, Brew.

By: Mercedes Yanora

Here’s what’s in store for you as you start your day:

Exclusive – Ballotpedia releases 14th Annual State Legislative Competitiveness Report
Did you know that 16% of state legislative primaries this year were contested?

Exclusive – Ballotpedia releases 14th Annual State Legislative Competitiveness Report

In the Sept. 20 edition of the Brew, we offered a sneak peek into our state legislative competitiveness work with a story highlighting major party competition both in Michigan and nationwide. Today, we’re pleased to deliver the full 14th Annual State Legislative Competitiveness Report!

Our data tell us that state legislative competitiveness in 2024 was below average for even years from 2010 to 2024. That doesn’t mean every component of competitiveness was below average, however—more on that below.

Key findings

The three states with the biggest increase in competitiveness from 2022 to 2024 are Tennessee (40%), Montana (38%), and Wisconsin (26%). The three states with the biggest decrease in competitiveness from 2022 to 2024 are Rhode Island (47%), Massachusetts (33%), and Alaska (33%).
The three most competitive states this year are Nebraska, California, and Montana. This is the first time since 2010 that Nebraska has been in the top three. California and Montana have been in the top three in 2012 and 2014, respectively.
The three least competitive states this year are Massachusetts, Alaska, and Rhode Island. Massachusetts has been the least competitive state in six of the last eight even-year elections. This is the first time Alaska has been in the bottom three since we began gathering data in 2010. Rhode Island has been in the bottom three in 2014, 2020, and 2024.

Competitiveness overview

First, let’s establish what makes up competitiveness. We use three factors to determine state legislative competitiveness:

Open seats, where no incumbent is running;

Incumbents in contested primaries, who could potentially lose to challengers; and

Major party competition — where Democrats and Republicans meet head-to-head in the general election.

The percentages for each of those factors are averaged to produce a State Legislative Competitiveness Index, which can range from zero (least competitive) to 100 (most competitive).

In 2024, this index stands at 33.3, down from the last three election cycles: 2022 (36.6), 2020 (33.4), and 2018 (36.1), and below the 14-year average of 34 for even-year elections. Looking at averages across the last three election cycles, 2024 has fewer open seats, incumbents in contested primaries, and seats with major party competition.

We get a more nuanced picture if we look at each factor separately.

But first, a quick note on methodology: For 2024 figures, we include the 44 states that are holding state legislative elections this year. Alabama, Louisiana, Maryland, Mississippi, New Jersey, and Virginia do not have state legislative elections this year. Because of this, we often directly compare 2024 figures to 2020 figures, instead of 2022, because 2020 was the last time the same 44 states held elections.

Additionally, the figures in this report may change slightly from now until the general election as we identify incumbents and other candidates who may either withdraw from or be added to the ballot.

Open seats

This year, there are 965 open state legislative seats, guaranteeing newcomers will win at least 17% of all seats. This is the second-smallest number of open seats since Ballotpedia began gathering data in 2010.

Note—the spikes in 2012 and 2022 are typical following redistricting, which results in more open seats from new maps being drawn.

A greater number of open seats guarantees more newcomers entering legislatures and typically results in more candidates running for office. A smaller number of open seats guarantees fewer newcomers and typically results in fewer candidates running for office.

Some highlights are below.

There are 409 open Democratic seats.
There are 546 open Republican seats.
There are 10 other open seats. This includes those most recently held by minor party or independent officeholders at the time of filing.
The total number of open seats—965—is higher than in 2020 (876), the last time all 44 states held elections, representing a 10% increase.

At least 30% of the seats on the ballot are open in five states: Nebraska (60%), Montana (42%), South Dakota (34%), California (34%), and Missouri (32%). Four of these states have Republican trifectas, and one has a Democratic trifecta.

Nebraska had the highest rate of open seats in four of the last eight election cycles. This is likely because Nebraska has only one, term-limited chamber, the Nebraska Senate. The Senate has the highest percentage of state senators term-limited this year. Thirteen of the 25 open seats, or 52% of the chamber, are due to term limits.

Term limits result in a greater percentage of open seats, which generally have higher contested rates because incumbents are forced to leave office after a certain time. In states with term limits, an average of 29% of seats were open in even years since 2010. In non-term limit states, the average percentage was 14%.

Incumbents in contested primaries

This year, the states with the highest percentages of incumbents in contested primaries are Wyoming (66%), South Dakota (61%), Nebraska (50%), Idaho (50%), Arizona (46%), and California (46%). Four of these states have Republican trifectas, one has a Democratic trifecta, and the other has a divided government.

Click here to view an interactive version of the chart.

This is the first year since Ballotpedia began gathering data in 2010 that a state had more than 65% of its incumbents in contested primaries. The only other year to have a state with an incumbent contested rate of at least 60% was 2022 with 61% in Idaho.

Of the 4,850 incumbents running for re-election nationwide, 22% (or 1,047) were contested in primaries. This is roughly average compared to previous years, down from 27% in 2022. The average was 20% in 2020 and 22% in 2018.

There were 367 Democratic incumbents in contested primaries, representing 17% of all Democratic incumbents who ran for re-election, a 26% decrease from 2020.
There were 680 Republican incumbents in contested primaries, representing 26% of all Republican incumbents who ran for re-election, a 33% increase from 2020.
The total number of incumbents in contested primaries—1,047—was higher than in 2020 (1,006), representing a 4% increase.

Major party competition

For the eighth election cycle in a row, Michigan has the highest percentage of contested state legislative elections at 99%. The lowest rate in the state, since Ballotpedia began gathering data in 2010, was 98% in 2010 and 2012. The highest rate was 100% in 2014, 2016, and 2018.

The only other state with a contested election rate of more than 90% this year is Minnesota at 95%. Maine (88%), Ohio (86%), and Montana (85%) follow Minnesota to round out the top five most contested states. Of the five, Minnesota is the only state without term limits.

Nationwide, 2,227 (38%) state legislative seats are uncontested and have no major party competition. This is roughly average compared to previous years, down from 41% in 2022. The average was 34% in 2018 and 35% in 2020.

Both parties are contesting the remaining 3,580 (62%) seats. This is higher than in 2022 (59%) but lower than in 2018 (66%) and 2020 (65%).

Democrats are guaranteed to win 1,107 seats (19%) that lacked Republican competition, a 7% increase from 2020. Republicans are guaranteed to win 1,116 seats (19%) that lacked Democratic competition, a 10% increase from 2020.

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While open seats, contested incumbents, and major party competition are the main factors we consider in this report, we still have more competitiveness data to offer. Click below for more analysis on:

Keep reading

Did you know that 16% of state legislative primaries this year were contested? In other words, out of 10,642 potential primaries this year, only 1,741 were contested—meaning they had more candidates running than available nominations.

This percentage is tied with 2014 (16%) as the lowest percentage of contested primaries since Ballotpedia began gathering data in 2010.

Click here to learn more about contested state legislative primaries.