BILLINGS, Mont. (AP) — Republican Tim Sheehy defeated three-term Democratic U.S. Sen. Jon Tester. The victory by the former U.S. Navy SEAL bolsters the GOP’s new Senate majority.

Sheehy closely aligned his campaign with Donald Trump and leading conservatives while painting Tester as a corrupt Washington insider. The Republican also promised to address the southern border crisis and curb government regulation.

Outside groups poured record-breaking amounts of money into the contest. Democrats entered the election with a narrow two-seat majority in the Senate. Tester — a moderate and the chamber’s only working farmer - was considered one of the most vulnerable Democrats on the ballot nationwide.

Republicans took control of the Senate on Tuesday night with wins in Ohio and West Virginia

Sheehy, 38, sought to dent the lawmaker’s reputation for authenticity by highlighting more than $500,000 that lobbyists and their families donated to Tester during the last election cycle.

The tactic mirrored Tester’s own 2006 campaign, when he beat a three-term Republican incumbent who got ensnared in a Washington, D.C. lobbying scandal.

Sheehy touted his military service and business experience, and pushed past questions raised over a bullet wound that he admitted lying about. He also sought to highlight his private sector success as the founder of an aerial firefighting company - even as the firm’s stock price tumbled.

Sheehy pitched the race as one of national importance for Republicans eager to undo four years of Democratic rule in the Senate and White House.

Tester was the last member of his party to hold statewide office in Montana and the last Democratic senator from the five-state Northern Plains region. When he first entered office in 2006, Democrats held six of the region’s 10 Senate seats.

Hoping to withstand the conservative wave that’s swept the region, Tester, 68, appealed to moderate Republicans and independents. That included pairing his Senate campaign with a ballot proposal enshrining abortion rights into the state constitution - along with frequent reminders to voters that he’s a working farmer who’s also worked hard for them.

He also tried to distance himself from Democratic presidential candidate Kamala Harris. He emphasized his support for abortion rights in hopes of appealing to moderate Republicans and independent voters.

Tester’s narrow 2006 victory over a three-term incumbent Republican marked a high point for Montana Democrats. It came in a mid-term election and amid growing dissatisfaction with the Bush administration’s war in Iraq.