2026 United States Senate election in South Dakota

2026 United States Senate election in South Dakota
← 2020
November 3, 2026
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Nominee Mike Rounds Brian Bengs
Party Republican Independent
Incumbent U.S. senator

Mike Rounds
Republican


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. Retired U.S. Air Force Lieutenant Colonel Brian Bengs, the Democratic nominee in 2022, is running as an independent.

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.

South Dakota is considered a red state. As of October 2026 voter registration was 331,873 Republican, 157,608 indepedent/non-affiliated, 135,324 Democratic, and 2796 Libertarian. The state is one of three (along with Nebraska and Idaho) in 2026 Senate election cycle where the Democratic nominee has withdrawn from the race, effectively clearing the field for an independent. Republicans have not lost a Senate election in South Dakota since 2008.[citation needed]

Republican primary

Candidates

Nominee

Eliminated in primary

  • Justin McNeal, Navy veteran and businessman

Endorsements

Mike Rounds
Executive branch officials
Organizations

Fundraising

Campaign finance reports as of March 31, 2026
Candidate Raised Spent Cash on hand
Justin McNeal (R) $1,555 $11 $1,543
Mike Rounds (R) $3,769,823 $2,515,470 $2,936,874
Source: Federal Election Commission

Polling

Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Mike
Rounds		 Justin
McNeal		 Undecided
Mason-Dixon Polling & Strategy April 7–11, 2026 500 (RV) ± 4.5% 66% 18% 20%
Hypothetical polling

Mike Rounds vs. Kristi Noem

Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Mike
Rounds		 Kristi
Noem		 Undecided
Kaplan Strategies June 12, 2023 500 (RV) ± 4.7% 26% 53% 21%

Kristi Noem vs. Dusty Johnson

Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Kristi
Noem		 Dusty
Johnson		 Undecided
Kaplan Strategies June 12, 2023 500 (RV) ± 4.7% 54% 23% 23%

Results

Primary results by county:
  Rounds
  •   60–70%
  •   70–80%
  •   80–90%
Republican primary results
Party Candidate Votes %
Republican Mike Rounds (incumbent) 101,284 75.8
Republican Justin McNeal 32,341 24.2
Total votes 133,625 100.0

Independent

Candidate

Declared

Fundraising

Campaign finance reports as of March 31, 2026
Candidate Raised Spent Cash on hand
Brian Bengs (I) $564,715 $511,174 $53,540
Source: Federal Election Commission

Democratic primary

Candidates

Withdrew after nomination

Fundraising

Campaign finance reports as of March 31, 2026
Candidate Raised Spent Cash on hand
Julian Beaudion (D) $192,473 $185,994 $6,478
Source: Federal Election Commission

General election

Predictions

Source Ranking As of
The Cook Political Report Solid R October 20, 2026
Decision Desk HQ Safe R October 22, 2026
The Economist Likely R October 21, 2026
FiftyPlusOne Safe R October 22, 2026
Fox News Solid R October 20, 2026
Inside Elections Solid R October 15, 2026
NBC News Solid R October 22, 2026
RealClearPolitics Solid R October 12, 2026
Sabato's Crystal Ball Safe R October 14, 2026
Silver Bulletin Solid R October 22, 2026
Split Ticket Safe R October 22, 2026

Post-primary endorsements

Mike Rounds (R)
Organizations
Newspapers
Brian Bengs (I)
Executive branch officials
Party officials
Political parties
News organizations
Julian Beaudion (D) (withdrawn)
Executive branch officials

Fundraising

Italics indicate a withdrawn candidate

Campaign finance reports as of October 14, 2026
Candidate Raised Spent Cash on hand
Mike Rounds (R) $5,148,217 $5,535,196 $1,295,543
Julian Beaudion (D) $247,595 $246,900 $695
Brian Bengs (I) $1,855,763 $1,786,055 $69,708
Source: Federal Election Commission

Polling

Aggregate polls
Source of poll
aggregation		 Dates
administered		 Dates
updated		 Mike
Rounds (R)		 Brian
Bengs (I)		 Other/
Undecided		 Margin
Silver Bulletin through October 21, 2026 October 26, 2026 53.4% 41.0% 5.6% Rounds +12.4%
Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Mike
Rounds (R)		 Brian
Bengs (I)		 Other Undecided
Emerson College October 19–20, 2026 803 (LV) ± 3.5% 50% 42% — 8%
Quantus Insights (R) October 17–19, 2026 633 (LV) ± 4.1% 59% 37% 2% 2%
57% 37% 2% 5%
Public Opinon Strategies (R) October 12–16, 2026 500 (LV) ± 4.4% 54% 37% 9%
Mason-Dixon Polling & Strategy October 12–14, 2026 500 (RV) ± 4.5% 56% 37% – 6%
Concord Public Opinion Partners (D) October 6–8, 2026 400 (LV) ± 4.9% 42% 43% 5% 10%
Zenith Research September 24–27, 2026 500 (LV) ± 4.4% 53% 47% — —
44% 38% — 17%
Public Policy Polling (D) September 8–9, 2026 629 (RV) ± 3.6% 45% 42% — 13%
Lake Research Partners (D) August 26–30, 2026 500 (LV) ± 4.4% 44% 51% — 5%
Impact Research (D) August 13–17, 2026 500 (LV) ± 4.4% 44% 44% — 12%
Public Opinion Strategies (R) July 6–9, 2026 500 (LV) ± 4.4% 56% 33% — 11%
June 2, 2026 Primary elections
Public Policy Polling (D) May 29–30, 2026 726 (RV) ± 3.6% 44% 40% — 16%
Public Policy Polling (D) February 17–18, 2026 685 (RV) — 47% 35% — 19%
Public Policy Polling (D) November 13–14, 2025 814 (RV) ± 3.3% 44% 31% — 25%
Public Policy Polling (D) July 30–31, 2025 524 (LV) ± 4.1% 41% 28% — 31%
Hypothetical polling
Mike Rounds vs. Julian Beaudion vs. Brian Bengs
Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Mike
Rounds (R)		 Julian
Beaudion (D)		 Brian
Bengs (I)		 Undecided
Public Policy Polling (D) May 29–30, 2026 726 (RV) ± 3.6% 43% 18% 23% 16%

Mike Rounds vs. Julian Beaudion

Poll source Date(s)
administered		 Sample
size		 Margin
of error		 Mike
Rounds (R)		 Julian
Beaudion (D)		 Undecided
Public Policy Polling (D) May 29–30, 2026 726 (RV) ± 3.6% 56% 31% 13%
Public Policy Polling (D) February 17–18, 2026 685 (RV) ± - 49% 32% 19%
Public Policy Polling (D) November 13–14, 2025 814 (RV) ± 3.3% 52% 30% 18%

Results

2026 United States Senate election in South Dakota
Party Candidate Votes % ±%
Republican Mike Rounds (incumbent)
Independent Brian Bengs
Total votes

Notes

  1. 1 2 3 4 5 6 Key:
    A – all adults
    RV – registered voters
    LV – likely voters
    V – unclear
  2. ↑ The Economist's prediction model uses unconventional terminology. For the purpose of equivalency, their "Very Likely" ratings are formatted as a "Likely" rating while "Likely" ratings are formatted as a "Lean" rating.
  3. ↑ Calculated by taking the difference of 100% and all other candidates combined.
  4. ↑ Leaners pushed
  5. ↑ "Someone else" with 2%
  6. ↑ "Someone else" with 2%
  7. ↑ With voters who lean toward a given candidate
  1. ↑ Poll sponsored by South Dakota News Watch and the Chiesman Center for Democracy at the University of South Dakota
  2. ↑ Poll sponsored by Rounds' campaign
  3. ↑ Poll conducted for South Dakota News Watch and the University of South Dakota
  4. ↑ Poll sponsored by Democrats for Education Reform
  5. 1 2 3 4 5 6 7 8 9 10 11 Poll sponsored by Bengs' campaign
  6. ↑ Poll sponsored by the NRSC

References

  1. ↑ Binday, Ben (August 4, 2026). "Democrat exits Senate race in South Dakota, clearing way for independent". The Washington Post. Retrieved August 4, 2026.
  2. ↑ Staff (August 21, 2023). "Democratic voter registration falls behind 'other' category in South Dakota". South Dakota Searchlight. Retrieved October 21, 2026.
  3. ↑ "Voter Registration Totals". Idaho Secretary of State. October 2026. Retrieved October 21, 2026.
  4. ↑ Shane Goldmacher, Shane Goldmacher (August 4, 2026). "Democrat Quits Senate Race in South Dakota, Clearing Way for Independent". The New York Times. Retrieved October 12, 2026.
  5. ↑ Walsh, Lori; Chilson, Josh (January 22, 2026). "Rounds announces U.S. Senate reelection bid". SDPB. Retrieved January 22, 2026.
  6. ↑ "Campaign roundup: Republican announces for US Senate, other races grow, polls and money info emerge". South Dakota Searchlight. November 1, 2025. Retrieved November 2, 2025.
  7. ↑ staff, Dakota News Now (April 5, 2026). "Justin McNeal to appear on ballot for US Senate in June 2 primary". Dakota News Now. Retrieved April 6, 2026.
  8. ↑ Dakota War College (July 21, 2025). "After GOP pokes at him on Facebook, President Trump has high and undenaible praise for Senator Rounds". Dakota War College. Retrieved July 21, 2025.
  9. ↑ "Thank You for Supporting Pro-Israel Incumbent Members of Congress". AIPAC Political Portal. Retrieved April 30, 2026.
  10. 1 2 3 4 "2026 Election United States Senate – South Dakota". fec.gov. Federal Election Commission. Retrieved July 21, 2025.
  11. ↑ Rifaat, Alexander (April 20, 2026). "Poll: Johnson widens lead in SD GOP governor race". South Dakota News Watch. Retrieved April 20, 2026.
  12. 1 2 Sneve, Joe (June 13, 2023). "Pollster says Noem strongest GOP official in South Dakota. But where's Marty Jackley?". The Dakota Scout. Retrieved December 24, 2025.
  13. ↑ Dausch, Dominik (April 30, 2025). "Former Democrat Brian Bengs launches independent bid for Mike Rounds' Senate seat in 2026". Argus Leader. Retrieved April 30, 2025.
  14. ↑ Staff (April 28, 2026). "Brian Bengs to appear on ballot for U.S. Senate at November 3 General Election". Dakota News Now. Retrieved October 26, 2026.
  15. ↑ Dausch, Dominik (April 10, 2025). "Democrat Julian Beaudion announces US Senate run for Republican Mike Rounds' seat in 2026". Argus Leader. Retrieved April 30, 2025.
  16. ↑ Langer, Reed (April 4, 2026). "Julian Beaudion to appear on ballot as Democratic U.S. Senate candidate". Kota Territory. Retrieved April 5, 2026.
  17. ↑ "2026 CPR Senate Race Ratings". Cook Political Report. Retrieved October 22, 2026.
  18. ↑ "2026 Senate Ratings". Decision Desk HQ. Retrieved October 22, 2026.
  19. ↑ "2026 Senate Forecast". The Economist. Retrieved October 22, 2026.
  20. ↑ "2026 Congressional Forecast". FiftyPlusOne. Retrieved October 22, 2026.
  21. ↑ Numa, Rémy (October 20, 2026). "Fox News Power Rankings: Trump country at a crossroads". Fox News. Retrieved October 22, 2026.
  22. ↑ "Senate Ratings". Inside Elections. Retrieved October 22, 2026.
  23. ↑ "The race for Congress: 2026 midterms". NBC News. Retrieved October 22, 2026.
  24. ↑ "Battle for the Senate 2026". RealClearPolitics. Retrieved October 22, 2026.
  25. ↑ "2026 Senate ratings". Sabato's Crystal Ball. Retrieved October 22, 2026.
  26. 1 2 Silver, Nate; McKown-Dawson, Eli (October 22, 2026) [August 11, 2026]. "FLIPR 2026 midterm election forecast". Silver Bulletin. Retrieved October 22, 2026 – via Substack.
  27. ↑ "Split Ticket 2026 Midterms Model". The Argument. Retrieved October 22, 2026 – via Substack.
  28. ↑ "South Dakota". National Rifle Association Political Victory Fund. Retrieved September 13, 2026.
  29. ↑ "Endorsement: Rhoden, Rounds and Jackley for South Dakota's top spots". Mitchell Republic. October 17, 2026. Retrieved October 19, 2026.
  30. 1 2 Hult, John (October 25, 2026). "Independent US Senate candidate in South Dakota backed by Forward Party". South Dakota Searchlight. Retrieved October 26, 2026.
  31. ↑ "Candidates". Forward Party. Retrieved April 8, 2026.
  32. ↑ "Endorsement: Rhoden, Rounds and Jackley for South Dakota's top spots". Mitchell Daily Republic. October 17, 2026. Retrieved October 26, 2026.
  33. ↑ Troli, Blake (June 18, 2026). "Special Interview: Democratic Senate Candidate Julian Beaudion on Biden endorsement, US-Iran deal and more". KOTATV. Retrieved August 25, 2026.
  34. ↑ Yost, Rae (October 22, 2026). "Keloland Poll: Rounds leads Bengs at 8%, Trump approval down". Keloland. Retrieved October 22, 2026.
  35. ↑ "South Dakota U.S. Senate Survey" (PDF). Quantus Insights. October 21, 2026. Retrieved October 22, 2026.
  36. ↑ Howard, Andrew (October 20, 2026). "In today's Score: GOP Sen. Mike Rounds drops an internal showing him up 17 points on independent Brian Bengs". Twitter. Retrieved October 21, 2026.
  37. ↑ Emily, DeCock; Wetsch, Molly (October 22, 2026). "Poll: Sen. Rounds leads challenger Bengs 56-37%". South Dakota News Watch. Retrieved October 23, 2026.
  38. ↑ "SD-Sen, Gov: Concord Public Opinion Partners (Oct. 2026)". Concord Public Opinion Partners. October 9, 2026. Retrieved October 16, 2026.
  39. ↑ Carlson, Adam (September 30, 2026). "South Dakota U.S. Senate General Election Poll Results". Zenith Research. Retrieved October 1, 2026.
  40. ↑ Anastácio, Nicholas [@NenoNicolosio] (September 10, 2026). "Another #SDSEN internal poll: A Public Policy Polling survey conducted for Brian Bengs (I) found him and Sen. Mike Rounds (R) within the margin of error" (Tweet). Retrieved September 11, 2026 – via X (formerly Twitter).
  41. ↑ "Lake Research Partners poll — South Dakota U.S. Senate". Politics & Polls Tracker. August 30, 2026. Retrieved October 2, 2026 – via LinkedIn.
  42. ↑ "New Polling in South Dakota's Senate Race". Impact Research. August 19, 2026. Retrieved August 28, 2026 – via DocumentCloud.
  43. ↑ Hobart, Jim (August 5, 2026). "Key Findings From a Statewide Survey of Likely General Election Voters in South Dakota" (PDF). Public Opinion Strategies. Retrieved August 6, 2026 – via Townhall.
  44. 1 2 3 4 "Trump Dusts Off Conspiracy Playbook". National Journal. Retrieved June 8, 2026.
  45. 1 2 "A Midterm Emergency?". National Journal. Retrieved June 6, 2026.
  46. ↑ Nicholas Anastácio [@NenoNicolosio] (October 30, 2025). "A little ol' #SDSEN poll from @njhotline: A Public Policy Polling survey conducted for 2022 nominee Brian Bengs (I) found Sen. Mike Rounds (R) ahead of him in a head-to-head race Rounds 41% Bengs 28% Undecided 31% July 30–31; 552 LVs; +/-4.1%" (Tweet). Retrieved December 4, 2025 – via X (formerly Twitter).
  47. ↑ "Hotline's Wake-Up Call!". National Journal. Retrieved December 4, 2025.
Official campaign websites