Kentucky GOP Rep. Thomas Massie lost his primary Tuesday night to President Donald Trump-backed challenger Ed Gallrein, according to the Associated Press. 

The race was called with Gallrein securing 54.4% of the vote, compared to Massie's 45.6%, with 72% of the vote in.

The loss ends the libertarian's decade-long career in the lower chamber and demonstrates the power of Trump's endorsement. 

Trump endorsed Gallrein earlier this year and War Secretary Pete Hegseth campaigned for the candidate Monday night.

Massie is known for being a libertarian, which has seen him frequently vote against his own party on budgetary matters, and he has emerged as one of the foremost Republican skeptics of Israel and the ongoing Iran war.

Massie's voting record has also made him something of a darling among libertarian-leaning Republicans and younger voters, with polling showing a stark age split between his supporters and those of Gallrein.

The race has showcased recent divisions within the Republican Party. Whereas Gallrein has portrayed himself as a Trump ally and supporter of Israel, Massie has leaned into his opposition to foreign entanglements and his independent streak.

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.