2026 United States Senate election in South Dakota

For related races, see 2026 United States Senate elections.

Not to be confused with 2026 South Dakota Senate election.

2026 United States Senate election in South Dakota

←  2020 November 3, 2026 2032 →

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 65.8% of the vote and has not stated whether he will run for re-election.

Republican primary

Candidates

Declared

• Justin McNeal, Navy veteran and businessman ^[1]

Filed paperwork

• Mike Rounds, incumbent U.S. senator (2015–present) (decision expected in January 2026) ^{[2] [3]}

Endorsements

Mike Rounds (not declared)

Executive branch officials

• Donald Trump, president of the United States (2017–2021, 2025–present) ^[4]

Fundraising

Campaign finance reports as of September 30, 2025
Candidate	Raised	Spent	Cash on hand
Mike Rounds (R)	$2,792,218	$1,656,323	$2,818,417
Source: Federal Election Commission [5]

Democratic primary

Candidates

Declared

• Julian Beaudion, former South Dakota state trooper, activist, and businessman ^[6]

Fundraising

Campaign finance reports as of September 30, 2025
Candidate	Raised	Spent	Cash on hand
Julian Beaudion (D)	$146,311	$114,730	$31,081
Source: Federal Election Commission [5]

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 ^[7]

Fundraising

Campaign finance reports as of September 30, 2025
Candidate	Raised	Spent	Cash on hand
Brain Bengs (I)	$154,886	$125,175	$29,710
Source: Federal Election Commission [5]

General election

Predictions

Source	Ranking	As of
Inside Elections [8]	Solid R	August 12, 2025
The Cook Political Report [9]	Solid R	October 14, 2025
Sabato's Crystal Ball [10]	Safe R	August 12, 2025
Race To The WH [11]	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) [12] [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. Key:
   A – all adults
   RV – registered voters
   LV – likely voters
   V – unclear

1. 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. Sivak, David (December 2, 2025). "Mike Rounds planning post-holiday reelection announcement". Washington Examiner. Retrieved December 2, 2025.
3. "FEC Form 2 for Report FEC-1482809". docquery.fec.gov. Retrieved December 5, 2025.
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. "2026 Election United States Senate - South Dakota". fec.gov. Federal Election Commission . Retrieved July 21, 2025.
6. 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.
7. 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.
8. "Senate Ratings". Inside Elections. Retrieved April 30, 2025.
9. "2026 CPR Senate Race Ratings". Cook Political Report. Retrieved April 30, 2025.
10. "2026 Senate ratings". Sabato's Crystal Ball. Retrieved February 13, 2025.
11. "2026 Senate Forecast". Race to the WH. Retrieved April 30, 2025.
12. "Hotline's Wake-Up Call!". National Journal. Retrieved December 4, 2025.
13. "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 Twitter.

External links

Official campaign websites

• Julian Beaudion (D) for U.S. Senate
• Brian Bengs (I) for U.S. Senate
• Justin McNeal (R) for U.S. Senate
• Mike Rounds (R) for U.S. Senate