Congressman Thomas Massie, one of the most outspoken Republican critics of United States President Donald Trump, lost his Kentucky primary race on Tuesday to Trump-backed former Navy SEAL Ed Gallrein in a result that highlighted the president’s continuing dominance within the Republican Party.
Massie’s defeat came after months of attacks from Trump and his allies over the congressman’s opposition to parts of the administration’s agenda, including military action against Iran, major tax legislation and unconditional US military aid to Israel.
The race became the most expensive congressional primary in US history, with more than $34m spent on campaign advertising and outreach efforts.
Gallrein defeated Massie by a margin of 55 percent to 45 percent and will now advance to the November midterm election.
At his victory event, Gallrein thanked Trump for his backing and described the outcome as a victory for Kentucky Republicans and their families.
The Kentucky result was widely viewed as a key test of Trump’s influence over Republican voters ahead of the 2026 midterm elections.
Trump repeatedly criticised Massie during the campaign, calling him “an obstructionist and a fool” while urging voters to support Gallrein.
Massie had defended his record by saying he voted with Trump “90% of the time,” but argued the administration demanded “100% compliance.”
In his concession speech, Massie warned against unconditional loyalty to the president, saying, “If the legislative branch always votes with the president, we do have a king.”
The race also drew national attention because of heavy outside spending, including millions of dollars from pro-Israel groups that opposed Massie’s stance on aid to Israel.
Elsewhere, several closely watched races across the United States moved into their next phase following Tuesday’s primaries.
In Georgia, Republican gubernatorial and Senate contests advanced to June 16 run-offs after no candidate secured a majority.
Pennsylvania Governor Josh Shapiro secured the Democratic nomination for re-election and will face Republican Stacy Garrity in November.
In Alabama, election disputes over newly redrawn congressional district boundaries overshadowed statewide races, with civil rights groups criticising the changes as harmful to Black voting power.
Oregon and Idaho also finalized several major gubernatorial, Senate and congressional matchups for the general election later this year.