Will South Dakota Host Its 1st Gubernatorial Primary Runoff in 2026?

A competitive four-candidate field puts the 35 percent threshold in doubt for the first time in 40 years

With just a few weeks until South Dakota’s primary election filing deadline closes, the 2026 battle for the Republican gubernatorial nomination is poised to be its most competitive in decades.

So competitive, in fact, that the party might not know its nominee after votes are counted from the June 2nd primary.

A recent Emerson College horse race poll found all four GOP candidates receiving double digit support and all shy of 30 percent: U.S. Representative Dusty Johnson (28 percent), business executive Toby Doeden (18 percent), Governor Larry Rhoden (17 percent), and House Speaker Jon Hansen (14 percent).

A 1985 South Dakota election law – first proposed decades earlier – requires a candidate for governor or federal office to win 35 percent of the primary vote to avoid a runoff among the top two candidates.

That law has not been triggered across the 32 gubernatorial, U.S. Senate, and U.S. House primary elections held in the state since 1986.

Nearly a quarter of the likely voters in the Emerson College poll were undecided, so it is still in the cards for a candidate to win the nomination in June outright.

Prior to 1986, primary candidates still needed to win 35 percent, but if none reached that mark the nominee was decided via party convention.

In elections for governor, that process occurred twice during the primary era – both more than 80 years ago. [The first gubernatorial primary in South Dakota was held in 1908].

In 1930, five candidates ran for the GOP nomination: Secretary of State Gladys Pyle, former State Senator, Lieutenant Governor, and Governor Carl Gunderson, former three-term State Senator Warren Green, former Brookings Mayor and sitting State Senator Carl Trygstad, and State Senator Brooke Howell.

At the May 6th primary, Pyle won a plurality 28.3 percent, followed by Gunderson (26.9 percent), Howell (19.2 percent), Trygstad (18.1 percent), and Green (7.4 percent).

It took 12 ballots, but Green, a resident of Hazel, came back from the lowest ranked candidate in the first half-dozen ballots to eventually winning the nomination over Pyle in second place.

The second and last time a primary for governor did not result in a candidate with 35 percent of the vote occurred in 1942 in a competitive four-candidate field in which first to last place was separated by less than eight percentage points.

Former Faulk County Attorney Joe Bottum led the way with 28.9 percent followed by former Attorney General Merrill Sharpe (25.7 percent), sitting Attorney General Leo Temmey (24.5 percent), and state Rural Credits Director Millard Scott (21.0 percent).

Sharpe was nominated at the June 8th convention on the third ballot.

South Dakota Republicans and Democrats have nominated several other gubernatorial candidates with a plurality of the primary vote over the years, but clearing the 35 percent threshold:

• 1908 (Republican): Wessington Springs State Bank president and State Senator Robert Vessey (38.7 percent)
• 1914 (Republican): Lieutenant Governor Frank Byrne (43.6 percent)
• 1934 (Republican): Dakota Farmer publisher William Allen of Aberdeen (47.9 percent)
• 1946 (Republican): Attorney General George T. Mickelson (44.8 percent)
• 1946 (Democrat): Wolsey farmer Richard Haeder (41.1 percent)
• 1950 (Republican): Attorney General Sigurd Anderson (35.3 percent)
• 1978 (Democrat): State Senator Roger McKellips (49.1 percent)
• 1986 (Republican): Former State Representative and Brookings County Attorney George S. Mickelson (35.3 percent)
• 1986 (Democrat): State Representative R. Lars Herseth (42.8 percent)
• 2002 (Republican): State Senator Mike Rounds (44.3 percent)

The South Dakota filing deadline to appear on the primary ballot closes on March 31st.

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