Eighteen Delaware state legislative incumbents face primary contests on September 15, 2026, the most at any point since 2010. This is a 157% increase in the number of incumbents facing challengers compared to 2024.
Seventeen of the contested incumbents are Democrats, and one is a Republican. Twelve are state representatives, and six are state senators.
Delaware has 24 contested state legislative primaries in 2026, up 100% from 2024. Of these, there are 20 for Democrats and four for Republicans. For Democrats, this is up from 10 in 2024, a 100% increase. Contested Republican primaries are up 100% from 2 in 2024.
In total, 106 major party candidates filed to run. Seventy-one are Democrats, and 35 are Republicans. All 41 House seats and 11 of 21 Senate seats are up for election.
Nine seats are open, meaning no incumbents filed. This means newcomers will make up at least 15% of the legislature next year. The average number of open seats each cycle from 2010 to 2024 was six.
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