Most Wisconsin state legislative incumbents facing primaries since 2010

Wisconsin has 50 contested state legislative primaries in 2024, an increase of 32% from 2022.

Twenty-three of these primaries are for Democrats, a 156% increase from nine in 2022. Twenty-seven primaries are for Republicans, a decrease of seven percent from 29 in 2022.

A new high of 27 incumbents face primary challenges, representing 31% of all incumbents running for re-election. The previous high was 15 incumbents in 2012. The average number of primaries to feature an incumbent each election cycle from 2010 to 2022 was nine.

Four of the 27 incumbents facing primary challenges are Democrats, and 23 are Republicans.

In total, 269 major party candidates—145 Democrats and 124 Republicans—filed to run. All 99 State Assembly seats and 16 of the 33 Senate seats are up for election. Thirty of those seats are open, meaning no incumbents filed. This ties with 2022 as the most open seats since tracking began in 2010. The average number of open seats each cycle from 2010 to 2020 was 21.

Wisconsin is one of 10 states with divided government. The state was a Republican trifecta from 2011 until 2019, when Governor Tony Evers (D) assumed office. Republicans currently have a 64-35 majority in the State Assembly and a 22-10 majority in the Senate.

Wisconsin’s state legislative primaries are scheduled for August 13.