By 
Northern Plains News Race Lab simulations give Gov. Larry Rhoden a slight edge over Toby Doeden in South Dakota’s July 28 Republican governor runoff.
The edge is not large. It depends on Rhoden doing what the model suggests he is best positioned to do: win most of U.S. Rep. Dusty Johnson’s voters, hold his own base, and keep House Speaker Jon Hansen’s voters from breaking hard toward Doeden.
Doeden still has a live path. He won the June 2 primary’s first round, and he begins the runoff with the most votes. But the simulation suggests his path is more fragile. He needs a lower-turnout, higher-anger electorate. He also needs Hansen voters and county-level Republican activists to matter more than Johnson voters and institutional Republicans.
That is the real July 28 test.
Doeden finished first June 2 with 31 percent. Rhoden, the sitting governor, finished second with 25 percent. Johnson finished third with 23 percent, and Hansen finished fourth with 21 percent, according to South Dakota Searchlight. No candidate reached the 35 percent needed to avoid a runoff.
The model is not a poll. It does not predict individual voter intent. It tests what must happen for either candidate to win.
Race Lab model gives Rhoden the cleaner path
Race Lab ran three vote-transfer scenarios using the June 2 vote totals: Doeden with 41,791 votes, Rhoden with 34,379, Johnson with 31,925, and Hansen with 28,390.
In the Rhoden consolidation scenario, Rhoden wins by about 6,575 votes. The model assumes Doeden keeps 90 percent of his first-round voters, Rhoden keeps 95 percent of his, Johnson voters break 65 percent for Rhoden and 20 percent for Doeden, and Hansen voters break 45 percent for Doeden and 35 percent for Rhoden. That produces about 63,348 votes for Rhoden and 56,772 for Doeden.
In the Doeden insurgency scenario, Doeden wins by about 11,058 votes. The model assumes Doeden keeps 92 percent of his voters, Rhoden keeps 90 percent, Johnson voters break 50 percent for Rhoden and 30 percent for Doeden, and Hansen voters break 60 percent for Doeden and 25 percent for Rhoden. That produces about 65,059 votes for Doeden and 54,001 for Rhoden.
In the low-turnout machinery scenario, Doeden wins by about 5,537 votes. The model assumes Johnson voters still favor Rhoden, but Hansen voters lean toward Doeden and Rhoden retains fewer first-round voters. That produces about 60,447 votes for Doeden and 54,910 for Rhoden.
The model’s bottom line is simple. Rhoden prevails if Johnson voters behave like institutional Republicans and Hansen voters split. Doeden prevails if the runoff becomes an activist-turnout election.
Johnson voters give Rhoden his opening
Johnson voters are the clearest opening for Rhoden.
Searchlight reported that Doeden’s comment about wanting to “put an end to Dusty’s career” likely alienated Johnson’s base, according to USD professor emeritus Michael Card. Hellwege told Searchlight that Johnson voters who return for the runoff will likely move toward Rhoden.
That does not mean all Johnson voters become Rhoden voters. Some may stay home. Some may choose Doeden out of anger at Washington, Johnson’s campaign, or the old Republican order. But Rhoden does not need all of them. He needs enough of them to erase Doeden’s first-round lead.
Johnson’s 23 percent likely contains more pro-business, institutional, and competence-minded Republicans than Doeden’s first-round base. That makes Johnson’s voters the most important bloc in the runoff.
Hansen voters keep Doeden alive
Hansen voters are harder to read.
Some are likely Doeden voters in a two-person race. They share anger at Pierre, suspicion of major development deals, and distrust of the business wing of the party.
Others may hesitate. Doeden attacked Johnson hard. Third-party groups and campaigns also bruised Hansen during the primary. Some Hansen voters may choose Rhoden as the safer Republican, while others may skip the runoff.
That is why the model treats Hansen voters as the swing bloc. If they split, Rhoden likely wins. If they move heavily to Doeden, Rhoden is in trouble.
Legislative voters sent a warning
The runoff also comes after Republican legislative voters appeared to pull back from parts of the 2024 revolt.
The 2024 primaries changed Pierre. Pipeline politics, property-rights anger, and opposition to economic-development deals helped defeat a wave of incumbent Republican lawmakers.
The fight began with Summit Carbon Solutions’ proposed carbon dioxide pipeline, which sought to use eminent domain through 23 eastern South Dakota counties, according to Bob Mercer’s KELOLAND Capitol Bureau report. Opponents helped defeat a dozen Republican incumbents in 2024. Voters later rejected a pipeline-related law at the ballot box. Pipeline opponents then took control of both Republican legislative caucuses.
The 2026 primary cut into that revolt.
Searchlight reported that 16 incumbent lawmakers lost June 2, and many came from the 2024 newcomer class. Sioux Falls Mayor Paul TenHaken’s South Dakotans for Common Sense PAC raised $340,500 and spent $214,000 to help shift the Legislature back from the 2024 insurgents. Searchlight also reported that only one of the South Dakota Freedom Caucus’ nine publicly listed members is expected to return to Pierre.
That helps Rhoden’s case. It suggests many Republican primary voters are tired of permanent revolt.
But legislative races are not a July runoff.
Lower turnout is Doeden’s best friend
Searchlight reported that early voting for the runoff begins June 12, ballots had to be printed by June 10, and voter registration remains open through July 13. It also reported that election analysts expect lower turnout and shifting loyalties to shape the result.
Julia Hellwege, director of the Chiesman Center for Democracy and a University of South Dakota associate professor of political science, told Searchlight that Doeden benefited from “fairly anti-government sentiment” among likely Republican voters. She also said special elections usually draw lower turnout, which can give more partisan voters more weight.
That is where county party machinery matters.
Doeden needs his voters to stay angry. He needs Hansen’s anti-Pierre voters to move his way. He needs county activists to make the runoff feel urgent.
Rhoden needs the opposite. He needs Republicans who rejected insurgent legislators in June to return in late July. He needs Johnson voters to see Doeden as a risk, not just as another Republican option.
July 28 tests whether anger scales
Doeden led the primary. He did not come close to a majority. Nearly 70 percent of Republican voters picked someone else.
Race Lab’s current read is Rhoden lean, high volatility.
Rhoden has the cleaner math because Johnson voters give him a natural pool to overtake Doeden. Doeden has the hotter path because low turnout can reward the most motivated wing of the party.
If July 28 acts like a normal Republican sorting election, Rhoden probably wins.
If it acts like a county-party activation drill, Doeden can still take it.
Sourcing and mission note: This analysis is based on unofficial June 2 election results, South Dakota Searchlight reporting on the governor runoff and legislative primaries, Bob Mercer’s KELOLAND reporting on the economic-development split inside the GOP, and a Northern Plains News Race Lab vote-transfer model. NPN is covering the runoff because the result will help decide whether South Dakota Republicans move back toward institutional governing or hand more power to the party’s anti-Pierre wing.
