Republican Sen. Mike Rounds leads Independent challenger Brian Bengs 56% to 37%, according to the latest South Dakota Poll sponsored by News Watch and the Chiesman Center for Democracy at the University of South Dakota.

The Oct. 12-14 survey of 500 likely voters by Mason-Dixon Polling and Strategy, ranked as one of the least-biased and most-factual pollsters, also found that 62% of independents support Bengs, while 30% support Rounds and 8% of independents are undecided.

Other findings from the U.S. Senate poll:

  • Thirty-four percent of respondents did not recognize Bengs’ name.
  • Bengs (46%) and Rounds (47%) effectively split younger voters, aged 18-34.
  • Thirty percent of independents polled said they would choose Rounds, a Republican, over Bengs, an Independent.
  • About two-third of respondents approve of Rounds’ job performance as senator; one-third don’t approve.

Rob Skjonsberg, campaign adviser for Rounds, said South Dakotans know and trust Rounds, who served in the Legislature, was governor from 2003 to 2011 and has been one of the state’s two U.S. senators since 2015.

“On Nov. 3, the footnote of this race is going to be about the fact that this was about common sense versus crazy,” Skjonsberg said. “That’s going to be the footnote.”

Analysis

Here are some observations from News Watch partners, political scientists and the candidates’ campaigns.

Bengs’ second Senate bid has unclear impact

Bengs saw slightly higher name recognition than two other candidates running against Republicans for office, Democrats Dan Ahlers and Nikki Gronli.

Emily Wanless, associate professor of government and international affairs at Augustana University in Sioux Falls, said some of that recognition could be through Bengs’ previous bid for Senate, where he ran against Republican U.S. Sen. John Thune as a Democrat in 2022.

Bengs has also seen more national media attention as he campaigns with other independent Senate hopefuls Dan Osborn of Nebraska and Seth Bodnar of Montana.

“With Bengs, I do think the independent caucus and the national attention that he’s gotten, the general interest in voters exploring outside of the two-party candidates, might garner him some attention as well,” Wanless said. “I don’t know that come Election Day everyone who identifies as an independent is really acting independently. But they like the idea of being open to a candidate outside of the two parties, and so he might be getting some traction from that.

“Bengs, while technically a loser in his previous Senate bid, developed a campaign infrastructure and developed name recognition across the state, such that like a ground league just doesn’t have yet. So it’s one thing to be outside of politics; it’s another thing to be outside of politics but having political aspirations in the past that will increase name recognition,” Wanless said.

The South Dakota Poll results have Bengs in a different spot than some others released by the Bengs campaign and other groups. A poll by Concord Public Opinion Partners showed Bengs and Rounds effectively tied at 43% to 42%.

“The Bengs campaign has spent over $100,000 on polling from various pollsters to get an accurate read of where the race is. Some have us up, some have us down. But the fact is that Mike Rounds’ allies wouldn’t be dumping so much money into this race if they really thought it was safe,” Clara Bronikowski, a representative from the Bengs campaign, said to News Watch in a statement.

Rounds maintains high approval rating

Julia Hellwege, associate professor of political science at the University of South Dakota in Vermillion, said that Rounds has a relatively high approval rating for a sitting senator, especially when compared to the approval rating of other national politicians like Thune and President Donald Trump – results of those poll questions are forthcoming.

Hellwege said that Rounds’ activity in Congress – which has stayed under the radar compared to Thune, who has served as Senate majority leader since January 2025 – could be helping him maintain favor among South Dakotans.

“Rounds is the junior senator. He also was a beloved governor who did really well as governor. That protects him, but he also really stays away from some of the more D.C.-esque concerning things,” Hellwege said.

South Dakota News Watch is an independent nonprofit. Read, subscribe for free and donate at sdnewswatch.org. Contact reporter/Report for America corps member Molly Wetsch: 605-531-7382/ molly.wetsch@sdnewswatch.org. Contact reporter Emily DeCock: 605-736-4396/ emily.decock@sdnewswatch.org.