2020 United States Senate election in Montana
The 2020 United States Senate election in Montana will be held on November 3, 2020, to elect a member of the United States Senate to represent the State of Montana, concurrently with the 2020 U.S. presidential election, as well as other elections to the United States Senate in other states, elections to the United States House of Representatives, and various state and local elections.
Originally this seat was projected to be a likely Republican hold. However, Steve Bullock, Montana's popular Democratic governor, entered the race on the last day to file, which has shifted the dynamics of the contest dramatically, and many political pundits now consider it a competitive race and potential pickup for Democrats.
Republican primary
Candidates
Nominee
- Steve Daines, incumbent U.S. Senator
Eliminated in the primary
- John Driscoll, former Democratic Speaker of the Montana House of Representatives
- Daniel Larson, hardware store manager
Endorsements
Results
Democratic primary
Candidates
Nominee
- Steve Bullock, incumbent Governor of Montana and former candidate for President of the United States in 2020
Eliminated in the primary
- John Mues, nuclear engineer and U.S. Navy veteran
Withdrawn
- Jack Ballard, former professor at Montana State University Billings '
- Wilmot Collins, mayor of Helena '
- Mike Knoles, mathematician, physicist, and data analyst ' '
- Cora Neumann, public health expert and founder of the Global First Ladies Alliance '
- Josh Seckinger, fishing guide '
Declined
- Michael Punke, writer and former U.S. ambassador to the World Trade Organization
- Brian Schweitzer, former Governor of Montana
- Kathleen Williams, former state representative and nominee for Montana's at-large congressional district in 2018
Endorsements
Results
Other candidates
Libertarian Party
After Susan Geise officially withdrew, the Montana Libertarian Party could name a replacement candidate for the general election.Withdrawn
- Eric Fulton, Republican candidate for District 65 of the Montana House of Representatives in 2014
- Susan Geise, Lewis and Clark County commissioner and former chair of the Montana Republican Party
Green Party
Nominee
- Wendie Fredrickson, former audit reviewer for Montana State Department of Public Health and Human Services
Eliminated in primary
- Dennis Daneke, retired college professor
Results
General election
Predictions
Endorsements
Polling
Aggregate Polls| Poll source | Date administered | Sample size | Margin of error | Steve Daines | Steve Bullock | Other / Undecided |
| July 11–16, 2020 | 700 | ± 3.7% | 47% | 44% | 9% | |
| July 11–13, 2020 | 873 | ± 4.2% | 49% | 47% | 3% | |
| July 9–10, 2020 | 1,224 | ± 2.8% | 44% | 46% | 10% | |
| June 17–26, 2020 | 517 | ± 4.3% | 43% | 47% | 10% | |
| April 10–27, 2020 | 459 | ± 4.6% | 39% | 46% | 15% | |
| April 14–21, 2020 | 712 | ± 4.6% | 46% | 49% | 5% | |
| March 12–13, 2020 | 903 | ± 3.3% | 47% | 47% | 6% |
University of Montana polls did not account for certain presumed withdrawals of major party candidates after their primaries in the following polls.
;Steve Daines vs Steve Bullock, Wilmot Collins, Mike Knoles, Cora Neumann, and John Mues
| Poll source | Date administered | Sample size | Margin of error | Democratic candidates | Steve Daines |
| February 12–22, 2020 | 498 | ± 4.4% | 53% | 47% |
;Steve Daines vs Jack Ballard, Wilmot Collins, and John Mues
| Poll source | Date administered | Sample size | Margin of error | Democratic candidates | Steve Daines |
| September 26 – October 3, 2019 | 303 | ± 5.6% | 36.2% | 63.8% |