In 2026, 70.5% of the state legislative incumbents running for election in South Dakota will face primary contests, a record high since 2010.
In total, 55 incumbents face contested primaries across the South Dakota House and Senate. The average number of incumbents contested each election cycle since 2010 was 24. All 55 of the contested incumbents are Republicans.
Republicans have a 32-3 majority in the Senate and a 65-5 majority in the House.
