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.

Michigan’s high contested election rate is unsurprising given the state’s swing state status. According to Sabato’s Crystal Ball, “Michigan will be one of the key battleground states … The Michigan Senate is not up in 2024, but the Michigan House is, and it will be hotly contested. In 2022, the Democrats flipped both chambers, and they maintain only a narrow majority in the House. Republicans wouldn’t need to gain many seats to flip the chamber, and the national GOP is focusing attention on it. A court-ordered remap of the House districts for 2024 made the Democrats’ majority slightly more vulnerable.”

On a national scale, 2,273 (39%) state legislative seats are uncontested and have no major party competition. This is roughly average compared to previous years, down from 41% in 2022 but higher than 34% and 35% in 2018 and 2020, respectively. The remaining 3,534 (61%) state legislative seats are contested by both major parties.

Democrats are guaranteed to win 1,129 seats (19%) that lacked Republican competition, a 10% increase from 2020, the last time all 44 states held elections. Republicans are guaranteed to win 1,143 seats (20%) that lacked Democratic competition, a 13% increase from 2020. Overall, Democrats are running for 4,663 seats (80%) and Republicans are running for 4,677 (81%).

A seat has major party competition when candidates from both major parties are on the general election ballot. When only one major party is running for a seat, it has no major party competition and is effectively guaranteed to the major party candidate on the ballot.

Ballotpedia uses the level of major party competition to help determine the overall competitiveness of an election cycle. A larger number of seats without major party competition indicates fewer options on the ballot, while a smaller number indicates more options.

The absence of major party competition can effectively guarantee that one party wins the number of seats needed for a simple or veto-proof majority. One of the two major parties is guaranteed a simple majority in 19 chambers across 14 states. Democrats are guaranteed simple majorities in six chambers and Republicans are guaranteed simple majorities in 13.

One of the two major parties is guaranteed a veto-proof majority in 13 chambers across 11 states. Democrats are guaranteed veto-proof majorities in four chambers and Republicans are guaranteed veto-proof majorities in nine.