My analysis of how Johnson and Hansen voters may break in the Doeden/Rhoden runoff assumes that voters will show up in the same numbers and factional proportions on July 28 as they did in last week’s primary.
One problem with that assumption is that runoffs usually have lower voter participation. Ranked-choice-voting advocacy group FairVote looked at runoffs for U.S. House and Senate primaries over the last 30 years and found turnout decreased from primary to runoff 97% of the time:
- In the 294 federal primary runoffs in 10 Southern states from 1994 to 2024, turnout has decreased from the primary to the runoff in 97% of contests – by a median of 41%.
- Turnout decline has been steadily increasing each cycle.
- In the 16 federal primary runoffs in 2024, turnout decreased by a median of 63%.
- Every 2024 primary runoff was decided by a margin smaller than the number of first-round voters who chose to stay home [Yates Wilburn, “Runoffs See 63% Decline in Voter Turnout, Report Finds,” FairVote.org, 2024.12.17].
FairVote’s analysis finds turnout goes down more when there’s more time between the primary and the runoff:
Since 1994, runoffs held within 30 days of the initial primary had a median turnout decline of 33%, while those with a gap greater than 30 days had a median decline of 48%. The marginal turnout decline for each day between primaries and runoffs (0.2%) shows that moving runoffs to a later date, even by a week, can potentially damage voter turnout [Rachel Hutchinson and Ben Fitzgerald, “Low Turnout and High Cost in Primary Runoffs, 1994–2024,” FairVote.org].
South Dakota’s Republican gubernatorial runoff takes place eight weeks, 56 days, after the primary. It’s not a federal runoff like those studied by FairVote, and it’s the first statewide runoff in South Dakota history, so we may see some uniquely South Dakota factors produce a different result. But runoffs everywhere suffer from the disadvantage of lacking multiple races to stir up voter interest. Last Tuesday, South Dakotans had three statewide offices, multiple Legislative contests, and local offices and ballot measures to vote on. In the runoff, Republican voters get just one two-man race to decide.
And don’t forget Dennis Daugaard’s wise observation after his gubernatorial primary win in 2010 that after a long primary, most voters just want to go to the lake. The lake factor will likely reduce the number of June 2 voters who head to the polls again on July 28.
Not only are we likely to see fewer voters in the Doeden/Rhoden runoff, but we will see a different mix of voters. According to election-tracking consultant MultiState.us, runoff voters are even “more engaged, ideologically motivated voters” than the folks who show up for primaries, “which generally means runoffs favor candidates with strong organizational backing or highly motivated base supporters.” A shift to fewer, arguably crazier Republicans should favor the candidate who can rouse the Trump loyalists, but note that in this South Dakota runoff, Doeden is borrowing Trump’s base, not really running on a base of his own, and Rhoden can make a play for that Trump base with his record (Exhibit 1: Operation Prairie Thunder, rounding up all those no-good brown people!). Rhoden can also win on organizational backing: Rhoden has a deeply talented campaign organization and lots of establishment orgs that will rally to his status-quo side, while newcomer Doeden just has a lot of his own money to buy ads.
The Republican runoff electorate likely won’t look like the primary participants in number or composition. But the strategy for winning the runoff is the same as for winning the primary: organize, motivate, and get out the vote… and maybe hand out free hot dogs at the lake.