South Dakota Republicans Head to Gubernatorial Runoff as Rhoden Faces Doeden Challenge

South Dakota Republicans will cast ballots Tuesday in a primary runoff to choose between Gov. Larry Rhoden and businessman Toby Doeden for their party’s gubernatorial nomination. The matchup became necessary after both candidates fell short of the 35% vote threshold required for an outright nomination win in the June 2 primary election. The victor will advance to face Democratic former state Sen. Dan Ahlers in November’s general election with substantial advantage in a state that has consistently favored Republicans and has not elected a Democratic governor since the 1970s.

Rhoden ascended to the governorship in early 2025 following the departure of former Gov. Kristi Noem, who left office to serve in President Donald Trump’s Cabinet. The Republican primary field also featured U.S. Rep. Dusty Johnson and state House Speaker Jon Hansen, with Doeden emerging as the top vote-getter at approximately 31 percent, followed by Rhoden at roughly 25 percent, Johnson at 23 percent, and Hansen at approximately 21 percent.

Two major population centers warrant close attention during the runoff count. Minnehaha County in the eastern portion of the state contains Sioux Falls, while Pennington County in the western region is home to Rapid City. Combined, these counties account for approximately one-third of the state’s registered Republicans and proved instrumental in Doeden’s primary success. Doeden narrowly prevailed in Minnehaha County and maintained approximately a 7-point advantage over Rhoden in Pennington County.

Rhoden’s pathway to the runoff emerged through strength in central and northwestern South Dakota, particularly in Meade, Lawrence, and Hughes counties, which encompass the state capital of Pierre and represent roughly 10 percent of registered Republicans. Lincoln County, located in suburban areas south of Sioux Falls and ranking as the state’s third-most populous county, may serve as a significant battleground given that neither candidate performed strongest there.

Polls close at 7 p.m. local time across South Dakota, translating to 8 p.m. Eastern Time in most areas observing Central Time and 9 p.m. Eastern Time in Mountain Time zones. Only registered Republicans are eligible to participate in the primary runoff, though Republicans who did not vote June 2 may still cast ballots Tuesday.

Approximately 322,000 active registered Republicans were on the rolls as of June 1, out of roughly 676,000 total registered voters statewide. The June 2 primary attracted approximately 136,000 votes, with historical data indicating that roughly 19 to 20 percent of primary votes are typically cast early or by absentee ballot.

The AP will declare a winner only after determining no mathematical path exists for the trailing candidate to overcome the margin. South Dakota does not conduct automatic recounts except in tied elections, though losing statewide candidates may request a recount if the margin is 0.25 percent or less of total votes cast.