Tim Sheehy emerged victorious in the Senate race for Montana on Wednesday, successfully ousting the current Democratic Senator Jon Tester, thus converting the seat to a Republican one.

The former Navy SEAL, new to politics, secured his win with 53% of the votes compared to Tester’s 45.2%, based on over 86% of votes reported early Wednesday. Sheehy garnered more than 271,800 votes while Tester received approximately 231,700 votes.

Sheehy’s win adds to the Republican party’s strength in the Senate. They needed to flip just two seats to regain a majority and successfully did so by also winning seats in Ohio and West Virginia earlier in the week.

Tester had served Montana as senator for 18 years, despite previous Republican successes in both state legislative chambers, the governor’s office, and the other U.S. Senate seat held by Republican Senator Steve Daines. His defeat marks a notable shift to the right in Montana’s political landscape over the last two decades.

This Senate race was one of the most costly of the election season, with both candidates reportedly spending over $260 million, and outside organizations contributing more than $155 million.