The 2024 United States Senate election in Montana was held on November 5, 2024, to elect a member of the United States Senate to represent the state of Montana. Republican businessman Tim Sheehy won his first term in office, defeating Democratic three-term incumbent Jon Tester.
Despite the state's heavy partisan lean in favor of the Republican Party, Tester remained popular among his constituents. Because of this and Montana's historical inclination to ticket-split, the race was considered to be competitive. Early polling showed Tester to be leading or nearly even, but Sheehy later gained an edge. Tester was widely seen as being the most vulnerable incumbent running for re-election, due to Montana's strong Republican lean and the decline of split-ticket voting.
Tester, a renowned centrist liberal, was first elected in 2006, when he narrowly defeated incumbent Republican senator Conrad Burns, and was reelected in 2012 and 2018. However, come Election Day in 2024, his vulnerability came to fruition as he lost his bid for a fourth term to Tim Sheehy by around 7.1 percentage points. Sheehy received roughly 52.6% of the statewide vote to Tester's 45.5%. Despite his loss, Tester still vastly outperformed Kamala Harris, who lost the state to Donald Trump in the concurrent presidential race by just under 20 percentage points. Tester also carried six counties that Trump concurrently won: Big Horn, Blaine, Hill, Lewis and Clark (Helena), Roosevelt, and Park. Tester received over 44,000 more raw votes than Harris, while Sheehy received over 32,000 fewer raw votes than Trump.
Along with Bob Casey Jr. in Pennsylvania and Sherrod Brown in Ohio, Tester was one of three incumbent senators to lose re-election in 2024. All three were first elected in 2006, defeating Republican incumbents, and won re-election in 2012 and 2018. This race was one of two 2024 U.S. Senate races in which Democratic senators sought re-election in states where Republican Donald Trump won in both the 2016 and 2020 presidential elections, the other being Ohio. With Sheehy's victory, Republicans held both of Montana's Senate seats for the first time since 1911.
Background Montana has generally been considered a red state at the federal executive level, voting for Republican candidates in each presidential election starting in 1996, when Bob Dole beat Bill Clinton by nearly 3 percentage points in a three-way race with Ross Perot. Since then, GOP candidates have won the White House race in the state by double digits in every race except in 2008. In the most recent presidential election, in 2020, Donald Trump beat Joe Biden in Montana by 56.92% to 40.55%. Republicans have also won all of the state's U.S. House elections since 1996. Within this time frame, Democrats have been more successful in elections for state offices and the U.S. Senate, with its governorship, state legislature, and Senate seats alternating between Democratic and Republican control. Leading up to the 2024 election, Republicans controlled both of Montana's U.S. House seats, the other U.S. Senate seat, the governorship, and had supermajority control of both houses of the state legislature.
Tester refused to endorse fellow Democrat Kamala Harris for president, a contributing factor towards the Senate race having been considered less nationalized. In 2012, the last election that featured Tester on the same ballot as the presidential election, Republican presidential candidate Mitt Romney won by 13.64%, while Tester won by 3.72% without receiving a majority (50%) of the vote..
Top-two primary proposal On April 4, 2023, Montana's State Senate passed a bill to institute a top-two primary system, but only for the 2024 U.S. Senate race. The bill's sponsor, Republican Greg Hertz, said it would require the winner of the 2024 Senate race to receive a majority of the vote. Incumbent Democrat Jon Tester won with a plurality of the vote in his 2006 and 2012 Senate campaigns, though he won a majority in 2018. Both Democrats and Libertarians alleged the bill was intended to prevent the Libertarian Party from placing a nominee on the general election ballot in the Senate race who could potentially pull votes away from the Republican nominee, with Democratic state senator Ryan Lynch calling it a "partisan power grab."
After the bill received backlash, Hertz introduced an amendment to make the use of a top-two primary for U.S. Senate elections permanent rather than sunsetting it after the 2024 race. The Montana House of Representatives State Administration Committee tabled the bill on April 19. An attempt to revive the bill failed, and the legislature adjourned without passing it, conclusively ending the push for a top-two primary.
Democratic primary Candidates Nominee Jon Tester, incumbent U.S. senator (2007–2025)
Eliminated in primary Michael Hummert, retired remodeling contractor
Endorsements
Fundraising Campaign finance reports as of May 15, 2024CandidateRaisedSpentCash on handJon Tester (D)$37,330,566$26,017,759$11,793,381Source: Federal Election Commission
Results
By county Source
County Jon Tester Michael Hummert Margin Total Votes % Votes % Votes % Votes Beaverhead44796.75% 15 3.25% 432 93.51%462Big Horn60095.69% 27 4.31% 573 91.39%627 Blaine41096.47% 15 3.53% 395 92.94%425Broadwater40595.52% 19 4.48% 386 91.04%424 Carbon1,08896.45% 40 3.55% 1,048 92.91%1,128 Carter2273.33% 8 26.67% 14 46.67%30 Cascade6,51896.49% 237 3.51% 6,281 92.98%6,755 Chouteau33599.11% 3 0.89% 332 98.22%338 Custer61194.88% 33 5.12% 578 89.75%644 Daniels4391.49% 4 8.51% 39 82.98%47 Dawson30294.97% 16 5.03% 286 89.94%318 Deer Lodge1,78398.18% 33 1.82% 1,750 96.37%1,816 Fallon5494.74% 3 5.26% 51 89.47%57 Fergus75196.41% 28 3.59% 723 92.81%779 Flathead7,82197.30% 217 2.70% 7,604 94.60%8,038 Gallatin13,31997.45% 348 2.55% 12,971 94.91%13,667 Garfield20100.00% 0 0.00% 20 100.00%20 Glacier1,09097.32% 30 2.68% 1,060 94.64%1,120 Golden Valley33100.00% 0 0.00% 33 100.00%33 Granite25496.58% 9 3.42% 245 93.16%263 Hill1,20096.00% 50 4.00% 1,150 92.00%1,250 Jefferson1,33097.15% 39 2.85% 1,291 94.30%1,369 Judith Basin15797.52% 4 2.48% 153 95.03%161 Lake2,77197.47% 72 2.53% 2,699 94.93%2,843 Lewis and Clark10,32597.30% 286 2.70% 10,039 94.61%10,611 Liberty8491.30% 8 8.70% 76 82.61%92 Lincoln1,23594.27% 75 5.73% 1,160 88.55%1,310 Madison65896.91% 21 3.09% 637 93.81%679 McCone6894.44% 4 5.56% 64 88.89%72 Meagher11792.86% 9 7.14% 108 85.71%126 Mineral24096.77% 8 3.23% 232 93.55%248 Missoula19,85897.48% 514 2.52% 19,344 94.95%20,372 Musselshell16896.00% 7 4.00% 161 92.00%175 Park2,43397.48% 63 2.52% 2,370 94.95%2,496 Petroleum1593.75% 1 6.25% 14 87.50%16 Phillips13894.52% 8 5.48% 130 89.04%146 Pondera36995.84% 16 4.16% 353 91.69%385 Powder River6495.52% 3 4.48% 61 91.04%67 Powell35596.99% 11 3.01% 344 93.99%366 Prairie6098.36% 1 1.64% 59 96.72%61 Ravalli3,53197.46% 92 2.54% 3,439 94.92%3,623 Richland27095.41% 13 4.59% 257 90.81%283 Roosevelt45993.67% 31 6.33% 428 87.35%490 Rosebud42797.94% 9 2.06% 418 95.87%436 Sanders91395.90% 39 4.10% 874 91.81%952 Sheridan16896.00% 7 4.00% 161 92.00%175 Silver Bow6,44796.63% 225 3.37% 6,222 93.26%6,672 Stillwater52496.32% 20 3.68% 504 92.65%544 Sweet Grass21796.02% 9 3.98% 208 92.04%226 Teton57897.14% 17 2.86% 561 94.29%595 Toole18894.47% 11 5.53% 177 88.94%199 Treasure3594.59% 2 5.41% 33 89.19%37 Valley44896.55% 16 3.45% 432 93.10%464 Wheatland8696.63% 3 3.37% 83 93.26%89 Wibaux3694.74% 2 5.26% 34 89.47%38 Yellowstone12,40196.19% 491 3.81% 11,910 92.38%12,892
Republican primary Candidates Nominee Tim Sheehy, founder and former CEO of Bridger Aerospace
Eliminated in primary Brad Johnson, former chair of the Montana Public Service Commission (2015–2023) and former Montana Secretary of State (2005–2009) Charles Walkingchild Sr., environmental contractor and candidate for in 2022
Withdrew Jeremy Mygland, construction company owner (endorsed Rosendale, ran for state senate) Matt Rosendale, U.S. representative from (2023–2025) and at-large district (2021–2023); nominee for U.S. Senate in 2018 (endorsed Sheehy)
Declined Greg Gianforte, governor of Montana (2021–present) (endorsed Sheehy, ran for re-election) Ryan Zinke, U.S. representative from (2023–present) and at-large district (2015–2017); former U.S. secretary of the interior (2017–2019) (endorsed Sheehy, ran for re-election)
Endorsements
Fundraising Campaign finance reports as of May 15, 2024CandidateRaisedSpentCash on handBrad Johnson (R)$42,967$39,697$3,270Tim Sheehy (R)$10,547,437$8,324,164$2,223,272Source: Federal Election Commission
Polling Poll source Date(s)administered Samplesize Marginof error BradJohnson MattRosendale TimSheehy Other /Undecidedco/efficient (R)November 12–14, 2023888 (LV)± 3.3%–24%40%36%Fabrizio, Lee & Associates (R) October 23–25, 2023 600 (LV) ± 4.0%6%35%38%21%0%41%44% 15%J.L. PartnersAugust 12–17, 2023418 (LV)––52%21%28%Public Policy Polling (D)June 19–20, 2023510 (LV)± 4.3%–64%10%26%
Poll source Date(s)administered Samplesize Marginof error RussellFagg BradJohnson MattRosendale TimSheehy CoreyStapleton RyanZinke Other /UndecidedOnMessage Inc. (R)February 18–21, 2023600 (LV)± 4.0%2%–36%2%6%26%28%
Results
By county Source