Ed Gallrein (R) defeated incumbent Rep. Thomas Massie (R) in the Republican primary for Kentucky's 4th Congressional District on May 19, 2026. Massie was the second member of the U.S. House of Representatives to lose re-election in a primary in the 2026 election cycle.
At the time of the election, this race was the only U.S. House primary in which President Donald Trump (R) endorsed a challenger to a Republican incumbent. After Massie said he would vote against the short-term government funding bill in March 2025, Trump posted on Truth Social that “HE SHOULD BE PRIMARIED, and I will lead the charge against him."
In response, Massie posted on X, “Someone thinks they can control my voting card by threatening my re-election. Guess what? Doesn’t work on me. Three times I’ve had a challenger who tried to be more MAGA than me. None busted 25% because my constituents prefer transparency and principles over blind allegiance.” Trump endorsed Gallrein on Oct. 17, 2025.
