2026 United States Senate election in South Dakota

The 2026 United States Senate election in South Dakota will be held on November 3, 2026, to elect a member of the United States Senate to represent the state of South Dakota. Republican incumbent Mike Rounds is seeking a third term. He is being challenged by independent military officer Brian Bengs.

Primary elections were held on June 2. Rounds received 75.8% of the vote against minimal opposition. Former state trooper Julian Beaudion won Democratic nomination unopposed, but withdrew from the race on August 4. Bengs, the Democratic nominee in 2022, filed to run as an independent.

Republicans have not lost a Senate election in South Dakota since 2008.

Republican primary Candidates Nominee Mike Rounds, incumbent U.S. senator (2015–present) Eliminated in primary Justin McNeal, Navy veteran and businessman

Endorsements

Fundraising Campaign finance reports as of March 31, 2026CandidateRaisedSpentCash on handJustin McNeal (R)$1,555$11$1,543Mike Rounds (R)$3,769,823$2,515,470$2,936,874Source: Federal Election Commission

Polling Poll source Date(s)administered Samplesize Marginof error MikeRounds JustinMcNeal UndecidedMason-Dixon Polling & StrategyApril 7–11, 2026500 (RV)± 4.5%66%18%20%

Mike Rounds vs. Kristi Noem Poll source Date(s)administered Samplesize Marginof error MikeRounds KristiNoem UndecidedKaplan StrategiesJune 12, 2023500 (RV)± 4.7%26%53%21%

Kristi Noem vs. Dusty Johnson Poll source Date(s)administered Samplesize Marginof error KristiNoem DustyJohnson UndecidedKaplan StrategiesJune 12, 2023500 (RV)± 4.7%54%23%23%

Results

Democratic primary Candidates Withdrew after nomination Julian Beaudion, former South Dakota state trooper, activist, and businessman

Fundraising Campaign finance reports as of March 31, 2026CandidateRaisedSpentCash on handJulian Beaudion (D)$192,473$185,994$6,478Source: Federal Election Commission

Independents Candidates Declared Brian Bengs, U.S. Navy and Air Force veteran, former Northern State University political science professor, and Democratic nominee for U.S. Senate in 2022

Fundraising Campaign finance reports as of March 31, 2026CandidateRaisedSpentCash on handBrian Bengs (I)$564,715$511,174$53,540Source: Federal Election Commission

General election Predictions SourceRankingAs ofThe Cook Political ReportSeptember 23, 2026Decision Desk HQOctober 2, 2026The EconomistOctober 3, 2026FiftyPlusOneOctober 3, 2026Fox NewsSeptember 22, 2026Inside ElectionsOctober 1, 2026RealClearPoliticsSeptember 24, 2026Sabato's Crystal BallSeptember 22, 2026Silver BulletinOctober 3, 2026Split TicketOctober 2, 2026

Post-primary endorsements

Fundraising Italics indicate a withdrawn candidate Campaign finance reports as of June 30, 2026CandidateRaisedSpentCash on handMike Rounds (R)$4,513,920$3,459,778$2,736,663Julian Beaudion (D)$192,473$185,994$6,478Brian Bengs (I)$782,049$730,644$51,405Source: Federal Election Commission

Polling Aggregate polls Source of pollaggregation Datesadministered Datesupdated MikeRounds (R) BrianBengs (I)Other/Undecided MarginSilver Bulletinthrough September 27, 2026October 6, 202651.0%43.5%5.5%Rounds +7.5%

Poll source Date(s)administered Samplesize Marginof error MikeRounds (R) BrianBengs (I) Other UndecidedZenith ResearchSeptember 24–27, 2026500 (LV)±4.4%53%47%44%38%17%Public Policy Polling (D)September 8–9, 2026629 (RV)±3.6%45%42%13%Lake Research Partners (D)August 26–30, 2026500 (LV)±4.4%44%51%5%Impact Research (D)August 13–17, 2026500 (LV)±4.4%44%44%12%Public Opinion Strategies (R)July 6–9, 2026500 (LV)±4.4%56%33%11% June 2, 2026 Primary electionsPublic Policy Polling (D)May 29–30, 2026726 (RV)±3.6%44%40%16%Public Policy Polling (D)February 17–18, 2026685 (RV)47%35%19%Public Policy Polling (D)November 13–14, 2025814 (RV)±3.3%44%31%25%Public Policy Polling (D)July 30–31, 2025524 (LV)±4.1%41%28%31%

Mike Rounds vs. Julian Beaudion vs. Brian Bengs Poll source Date(s)administered Samplesize Marginof error MikeRounds (R) JulianBeaudion (D) BrianBengs (I) UndecidedPublic Policy Polling (D)May 29–30, 2026726 (RV)±3.6%43%18%23%16%

Mike Rounds vs. Julian Beaudion Poll source Date(s)administered Samplesize Marginof error MikeRounds (R) JulianBeaudion (D) UndecidedPublic Policy Polling (D)May 29–30, 2026726 (RV)±3.6%56%31%13%Public Policy Polling (D)February 17–18, 2026685 (RV)±-49%32%19%Public Policy Polling (D)November 13–14, 2025814 (RV)±3.3%52%30%18%

Notes

References

External links Official campaign websites Brian Bengs (I) Mike Rounds (R)