Delaware State Legislative Incumbents Face Record Number of Primary Challenges Since 2010
Eighteen Delaware state legislative incumbents are facing primary contests on September 15, 2026, marking the highest number of such challenges since 2010. This represents a 157% increase in incumbents facing challengers compared to 2024. Of these, seventeen contested incumbents are Democrats, and one is a Republican. The challenges are split between twelve state representatives and six state senators. Overall, Delaware has 24 contested state legislative primaries in 2026, a 100% increase from 2024. This includes 20 primaries for Democrats and four for Republicans. A total of 106 major party candidates have filed to run, with 71 Democrats and 35 Republicans. All 41 House seats and 11 of 21 Senate seats are up for election. Additionally, nine seats are open, meaning no incumbents filed, which will result in newcomers making up at least 15% of the legislature next year, exceeding the average of six open seats per cycle from 2010 to 2024. 
