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. Incumbent Democratic Senator Jon Tester lost re-election to a fourth term, being defeated by Republican nominee Tim Sheehy.
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 less 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.
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.
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.
Senator Jon Tester made some moves to distance himself from the Joe Biden administration, but his voting record remained in line with the Democratic Party. In July 2024, he called for Biden to withdraw from the 2024 United States presidential election. In August, he announced that he would not endorse Kamala Harris for president.
Hank Green, an American YouTuber, author, and educator known for his work on the educational series Crash Course, served as a moderator at an event for Tester in Missoula, Montana, in August 2024. He led a Q&A session alongside musician Jeff Ament, discussing local issues and encouraging voters to participate in the November election.
Sheehy received $8 million from billionaire Stephen Schwarzman and at least 63 other billionaires and 37 of their immediate family members, who donated about $47 million to SheehyâÂÂs Senate race.
Recordings first reported by The Char-Koosta News in August 2024 of Tim Sheehy at a 2023 closed-door fundraiser led to accusations that he had racially stereotyped Montana's Crow people. In one statement about how he ropes and brands cattle with Crow tribe members, he said it is "a great way to bond with all the Indians while they're drunk at 8 a.m." Sheehy said the tapes had been "chopped up". Tribal leaders requested an apology, but Sheehy declined.
Michael Downey, the winner of the Green Party primary election, dropped out of the race on August 12, citing the possibility that he might be a spoiler candidate in a close race. The Green Party of Montana selected the runner-up, Robert Barb, to replace Downey. The Montana Democratic Party filed a lawsuit asking for Barb to be removed from the ballot because of allegations that the Montana Green Party did not follow its procedure for designating a replacement candidate. Kathy Seeley, the district court judge hearing the case, denied the request. The Montana Democratic Party appealed to the Montana Supreme Court, but the justices refused to hear the case, leaving Barb on the ballot.
In October 2024, total spending for both sides (including both campaign spending and Independent expenditures), was on track to exceed $315 million. With Montana having only 648,000 active registered voters, the amount spent averaged $487 per voter, making the race the most expensive congressional campaign in U.S. history on a per voter basis. Democrats outspent Republicans by $50 million. Most of the money came from out-of-state dark money groups.
Aggregate polls<br />
Jon Tester vs. Greg Gianforte<br />
Jon Tester vs. Brad Johnson<br />
Jon Tester vs. Matt Rosendale<br />
Jon Tester vs. Ryan Zinke<br />
Counties that flipped from Democratic to Republican
Sheehy and Tester each won one of two congressional districts, with Tester narrowly winning the 1st district, which elected a Republican representative.
Partisan clients<br />
Official campaign websites