Republican Tim Sheehy has dramatically increased his chances of winning the potentially crucial Montana Senate seat over Democratic incumbent Jon Tester, according to a poll.
A Napolitan News survey, conducted by RMG Research, of 491 likely voters found that 50 percent would back Sheehy, compared to 43 percent who would support Tester in November. In a previous Napolitan survey conducted in August, Tester was ahead in the Montana Senate race by 5 points (49 percent to 44).
The outcome of the Senate race between Tester and Sheehy, along with the general election between Donald Trump and Kamala Harris in November, could end up determining who controls the upper chamber next year.
The Democrats currently control the Senate by a 51-49 seat margin, including four independent senators who caucus or align with the party. The GOP are expected to flip the West Virginia seat held by outgoing independent Senator Joe Manchin—giving Republicans an estimated 50 seats at least.
If Tester wins the Senate race, but Trump wins the presidential election, Republican vice president JD Vance will act as tiebreaker in Senate votes. If Harris wins the presidential election, the Democratic vice president Tim Walz will be tiebreaker in a 50-50 split.
If Sheehy wins the Montana seat, the GOP will be on course for 51-49 outright control of the upper chamber from January 2025, barring upsets elsewhere.
Montana Republican U.S. Senate candidate Tim Sheehy at a rally for Republican presidential nominee Donald Trump in Bozeman. Sheehy leads Democrat Jon Tester by seven points in a poll.
Michael Ciaglo/Getty Images
The Napolitan News survey also suggests that Sheehy has an advantage in the race if voters believed results would decide who controls the Senate.
In this scenario, 57 percent of Montana voters said they would vote for a Republican candidate.
Sheehy and Tester’s offices have been contacted for comment via email.
The Napolitan News survey was conducted by RMG Research, a company founded by pollster Scott Rasmussen, who also set up polling company Rasmussen Reports.
While sharing the latest poll results, Rasmussen suggested that the reason for the surge in support for Sheehy between August and September’s results are “Republican voters coming home.”
“In the summer, Sheehy had only a 53 point advantage among Republicans (72% to 19%). Now he’s up by 71 within his own party (81% to 10%),” Rasmussen posted on X, formerly Twitter
Rasmussen Reports, which Rasmussen left in 2013, has long been accused of being unreliable due to apparent bias as their results are thought to lean toward Republican candidates.
In March 2024, polling and forecasting website 538, formerly FiveThirtyEight, dropped Rasmussen Reports from its list of usable polling companies for failing to meet its standards.
Elsewhere, the September poll shows Trump is widely expected to retain Montana in November, leading Harris by 21 points (59 percent to 38).
The Napolitan News survey of 491 likely voters was conducted online between September 12-19. The results have a margin of sampling error of plus or minus 4.4 percentage points.
