South Dakota voters went to the polls Tuesday in primary elections that will determine nominees for governor, U.S. Senate, U.S. House and other state offices, with several high-profile Republican contests heading toward potential runoffs under the state's 35% vote threshold requirement.
Republican Gov. Larry Rhoden is seeking a full term after serving less than half of one following his ascent from lieutenant governor when Kristi Noem stepped down in early 2025 to join President Donald Trump's Cabinet. The crowded GOP primary featured four major candidates, with Trump notably declining to endorse any gubernatorial candidate despite backing other South Dakota Republicans.
The competitive governor's race included U.S. Rep. Dusty Johnson, State House Speaker Jon Hansen and businessman Toby Doeden alongside Rhoden. Whoever emerges from the Republican side will face former state Sen. Dan Ahlers in November. Ahlers ran unopposed for the Democratic nomination. The winner of Tuesday's primary needed at least 35% of votes to avoid a June 23 runoff.
What the Left Is Saying
Democrats acknowledged the steep challenges facing their candidates in South Dakota, one of the most reliably Republican-voting states in general elections. The party focused on down-ballot races and local organizing efforts rather than expecting upset victories.
Former state Sen. Dan Ahlers, running unopposed for the Democratic gubernatorial nomination, emphasized his legislative experience and rural outreach strategy. The Democratic Party pointed to economic concerns in agricultural communities as potential vulnerabilities for Republican candidates, though strategists privately acknowledged the state's political leanings make competitive statewide wins difficult.
The Democratic Governors Association indicated it would monitor results for turnout patterns that could inform future investment decisions, while noting that local races in Sioux Falls and legislative contests represent more realistic targets than the governor's mansion.
What the Right Is Saying
Republicans expressed confidence in their candidates' general election positioning, with officials emphasizing South Dakota's strong conservative bent. The party highlighted Trump's endorsements of Sen. Mike Rounds for his third Senate term and State Attorney General Marty Jackley to replace Johnson in the U.S. House.
Trump has not taken a position in the governor's race, leaving Republican voters to choose among Rhoden, Johnson, Hansen and Doeden based on other factors. Party officials noted that several candidates bring legislative or executive experience valuable to state governance.
Conservative commentators pointed to Rhoden's handling of his partial term as evidence of continuity with Noem's policies, while supporters of Johnson's congressional background argued federal experience matters for a border state dealing with national policy issues.
What the Numbers Show
About 674,000 registered voters were eligible to participate in Tuesday's primaries: approximately 318,000 Republicans, 138,000 Democrats and 157,000 independents or non-affiliated voters. South Dakota allows independent voters to participate in Democratic primaries but not Republican ones.
As of May 26, roughly 17,000 ballots had already been cast early, with about 79% in the Republican primary and approximately 15% in the Democratic primary. Early voting represented roughly 19% of total primary votes in 2024 and 20% in 2022.
In the state's most recent U.S. Senate primary in 2022, nearly 119,000 votes were cast in the Republican contest. Polls closed at 7 p.m. local time, with some counties in Mountain time closing at 9 p.m. ET. State law prohibits result releases until all polls close statewide.
The 35% threshold applies to governor, U.S. Senate and U.S. House primaries. If no candidate reaches that mark, the top two vote-getters advance to a June 23 runoff. Key counties to watch were Minnehaha County in the east, home to Sioux Falls, and Pennington County in the west, home to Rapid City.
The Bottom Line
The South Dakota primary results will determine which Republicans advance toward November's general election in a state where GOP nominees historically hold significant structural advantages. With multiple competitive races potentially triggering runoffs on June 23, voters may return to the polls within three weeks depending on whether any candidate clears 35%.
Republican control of all statewide offices and the state's congressional delegation is virtually certain regardless of Tuesday's outcomes given South Dakota's general election voting patterns. The primary's significance lies in determining which individuals will hold those positions rather than changing party control.
Voter turnout data, particularly in Minnehaha and Pennington counties, will indicate enthusiasm levels heading into the 2026 midterm cycle. Results are expected to be finalized by early Wednesday morning following vote counting across the state's two time zones.