The former Navy SEAL Tim Sheehy has won the Montana Senate GOP Primary Tuesday. He will now face Sen. Jon Tester, (D-MT), in a hotly contested General Election that could determine the party control of this chamber.

Sheehy was declared the winner by the Associated Press at 8:37 p.m. Mountain Time, 37 minutes after polls closed. Sheehy was in the lead with 74% of votes after less than half the ballots were counted.

Sheehy is supported by the former president Donald Trump. He beat out former Montana Public Service commissioner Brad Johnson, and former congressional candidate Charles Walking Child. Sheehy won the election after Rep. Matt Rosendale (R-MT), who had been in the race for only six days, stepped down.

The Republicans believe their best chance of gaining a majority in the Senate is to win over red states dominated by Trump and remove Tester. Tester’s fourth consecutive term bid hinges on convincing voters that he’s not like President Joe Biden.

Steve Daines, chair of the Senate GOP campaign arm, said that Montana is the clearest route to a Republican Senate majority. “Tim Sheehy is going to deliver a Senate major for President Trump. Jon Tester wants a Senate major for Joe Biden. This is the choice for this election.

Tester won easily against Michael Hummert on Tuesday, the Democratic challenger who had not filed any reports of campaign finances and didn’t appear to have a budget.

Democrats can’t afford to lose Montana, or any other of the half-dozen Senate races that are in battle, if they want to maintain majority control.

Tester has distanced himself more and more from Biden as the incumbent tries to gain enough Republican support in a state that Trump won by 16 points in 2020.

Sheehy was the target of an attack ad by Senate Democrats and a fundraising pitch by Tester’s camp within minutes of Sheehy winning.

Shelbi Daniel, the Tester campaign manager, framed the race as a contest between “a third-generation farmer who understands Montana’s lifestyle and will defend it relentlessly, and Tim Sheehy a multi-millionaire from out of state who is running for his own benefit and cannot be trusted to safeguard Montana.”