So far this year, 43 state legislative incumbents—eight Democrats and 35 Republicans—have lost to primary challengers.

Across the 14 states that have held primaries, 2.6% of incumbents running for re-election have lost, or 11.4% of the incumbents who were contested. That represents a 31% decrease from 2024 and sits 23% below the average of 56 incumbent losses each year from 2010 to 2024.

With 44 primaries featuring incumbents still uncalled across eight of these states, these figures are likely to change. Eleven of the uncalled primaries are for Democrats, and 33 are for Republicans.

Republican incumbents have lost at a higher rate than Democrats. Of the 1,057 Republican incumbents who filed for re-election, 35 (3.3%) have lost to primary challengers. For Democrats, eight of the 613 who filed for re-election (1.3%) have lost.

Three states so far saw more than 5% of the incumbents who ran for re-election lose in the primaries—Indiana, North Carolina, and West Virginia.

Of the 14 states that have held primaries so far, two have Democratic trifectas, nine have Republican trifectas, and three have divided governments.

The next set of state legislative primaries is scheduled for June 2 and will include California, Iowa, Montana, New Mexico, and South Dakota.