2026 United States Senate election in South Dakota

2026 United States Senate election in South Dakota

November 3, 2026
 
Party Republican Democratic

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. Primary elections will be held on June 2, 2026, with a runoff election held on July 28 if no candidate receives at least 35% of the vote in their respective primaries. Two-term Republican Mike Rounds was re-elected in 2020 with 65.7% of the vote and is running for re-election to a third term. South Dakota has been represented in the U.S. Senate exclusively by Republicans since 2015.

Republican primary

Candidates

Declared

  • Justin McNeal, Navy veteran and businessman[1]
  • Mike Rounds, incumbent U.S. senator (2015–present)[2]

Potential

Endorsements

Mike Rounds
Executive branch officials

Fundraising

Campaign finance reports as of December 31, 2025
Candidate Raised Spent Cash on hand
Justin McNeal (R) $130 $5 $125
Mike Rounds (R) $3,188,339 $1,975,401 $2,895,460
Source: Federal Election Commission[5]

Polling

Hypothetical polling

Mike Rounds vs. Kristi Noem

Poll source Date(s)
administered
Sample
size[a]
Margin
of error
Mike
Rounds
Kristi
Noem
Undecided
Kaplan Strategies[6] June 2023 500 (RV) 26% 53% 21%

Kristi Noem vs. Dusty Johnson

Poll source Date(s)
administered
Sample
size[a]
Margin
of error
Kristi
Noem
Dusty
Johnson
Undecided
Kaplan Strategies[6] June 2023 500 (RV) 54% 23% 23%

Democratic primary

Candidates

Declared

Fundraising

Campaign finance reports as of December 31, 2025
Candidate Raised Spent Cash on hand
Julian Beaudion (D) $179,539 $153,834 $25,205
Source: Federal Election Commission[5]

Independents

Candidates

Declared

Fundraising

Campaign finance reports as of December 31, 2025
Candidate Raised Spent Cash on hand
Brain Bengs (I) $329,131 $284,587 $44,544
Source: Federal Election Commission[5]

General election

Predictions

Source Ranking As of
Inside Elections[9] Solid R August 12, 2025
The Cook Political Report[10] Solid R October 14, 2025
Sabato's Crystal Ball[11] Safe R August 12, 2025
Race To The WH[12] Safe R September 4, 2025

Polling

Mike Rounds vs. Julian Beaudion

Poll source Date(s)
administered
Sample
size[a]
Margin
of error
Mike
Rounds (R)
Julian
Beaudion (D)
Undecided
Public Policy Polling (D)[13][A] November 13–14, 2025 814 (RV) ± 3.3% 52% 30% 18%

Mike Rounds vs. Brian Bengs

Poll source Date(s)
administered
Sample
size[a]
Margin
of error
Mike
Rounds (R)
Brian
Bengs (I)
Undecided
Public Policy Polling (D)[13][A] November 13–14, 2025 814 (RV) ± 3.3% 44% 31% 25%
Public Policy Polling (D)[14][A] July 30–31, 2025 524 (LV) ± 4.1% 41% 28% 31%

Notes

  1. ^ a b c d Key:
    A – all adults
    RV – registered voters
    LV – likely voters
    V – unclear
  1. ^ a b c Poll sponsored by Bengs' campaign

References

  1. ^ "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.
  2. ^ Walsh, Lori; Chilson, Josh (January 22, 2026). "Rounds announces U.S. Senate reelection bid". SDPB. Retrieved January 22, 2026.
  3. ^ Scherer, Michael (February 19, 2026). "The Buzz in Kristi Noem's Home State". The Atlantic. Retrieved February 20, 2026.
  4. ^ 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.
  5. ^ a b c "2026 Election United States Senate - South Dakota". fec.gov. Federal Election Commission. Retrieved July 21, 2025.
  6. ^ a b 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.
  7. ^ 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.
  8. ^ 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.
  9. ^ "Senate Ratings". Inside Elections. Retrieved April 30, 2025.
  10. ^ "2026 CPR Senate Race Ratings". Cook Political Report. Retrieved April 30, 2025.
  11. ^ "2026 Senate ratings". Sabato's Crystal Ball. Retrieved February 13, 2025.
  12. ^ "2026 Senate Forecast". Race to the WH. Retrieved April 30, 2025.
  13. ^ a b "Hotline's Wake-Up Call!". National Journal. Retrieved December 4, 2025.
  14. ^ 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).
Official campaign websites