By Nathan Layne
May 19 (Reuters) - U.S. President Donald Trump is targeting Representative Thomas Massie in Tuesday’s Republican primary in Kentucky, backing a challenger to try to purge one of his loudest critics from within the party.
The party contest - the most expensive U.S. House of Representatives primary in history - will again test Trump's hold over Republicans after he successfully pushed out another key critic, Senator Bill Cassidy of Louisiana, and scored victories against dissenting incumbents
in Indiana.
If Massie loses, it will reinforce Trump’s dominance over core supporters in the party ahead of the November midterm elections and send a warning to other Republicans about the political cost of defiance.
Massie incurred Trump's ire by successfully leading a push to release files tied to the late sex offender Jeffrey Epstein, and his criticism of the Iran war.
In a Sunday post on Truth Social, Trump called Massie "the worst and most unreliable Republican Congressman in the history of our Country," urging Kentuckians to "vote the bum out."
The contest between the libertarian‑leaning Massie and Trump‑backed Ed Gallrein, a former Navy SEAL, has attracted more than $30 million in ad spending, according to tracking firm AdImpact.
Other primaries are unfolding on Tuesday across Alabama, Georgia, Idaho, Kentucky, Oregon, and Pennsylvania, helping to shape the battlefield for November's elections, when Democrats aim to take control of the House and potentially the Senate despite Republican gains in a national redistricting fight.
But the fight for Massie’s district — spanning Louisville’s suburbs, the Kentucky side of the Cincinnati metro area, and rural counties to the east on the edge of Appalachia — is shaping up as the day's marquee contest.
Stephen Voss, a political science professor at the University of Kentucky, said the race was “a battle between ideological purity and party unity” in a conservative district where Trump is overwhelmingly popular but Massie’s buck‑the‑establishment brand of libertarianism also runs deep.
"A Massie victory will be seen as a sign that it's okay for Republicans to go up against Donald Trump if they do so with a clear vision," Voss said. A Massie loss would "strike fear in the hearts of other Republicans who want to keep their jobs as elected officials."
In a win for the president's retribution campaign, Cassidy lost in Louisiana's primary on Saturday after being targeted for his 2021 vote to convict Trump on impeachment charges. He is the first sitting U.S. senator to lose renomination since 2012.
Cassidy's defeat followed the president's successful effort to exact revenge on Indiana Republican state senators who blocked his redistricting push, with at least five incumbents unseated in primaries on May 5 by Trump-backed opponents.
OUTSIDE MONEY
Massie's votes against U.S. aid to Israel have drawn a surge of money from pro‑Israel groups into the race, with the Republican Jewish Coalition and the American Israel Public Affairs Committee spending heavily to oust him. Millions more have come from a Trump‑aligned super PAC backed by pro‑Israel donors such as hedge fund manager Paul Singer and casino magnate Miriam Adelson.
In contrast, Massie says his average donation is under $94, with roughly 33,000 donors nationwide.
Combined spending has reached $32 million, surpassing the $25 million spent in a 2024 race to oust Democratic Representative Jamaal Bowman in New York, according to AdImpact.
Public polling suggests the Massie-Gallrein race remains close. A May 11 to 12 Quantus Insights survey of 908 voters found 48.3% backing Gallrein and 43.1% for Massie, while a separate Big Data Poll survey of 518 registered Republicans released on Friday put Massie ahead by 1 percentage point.
Both polls reveal a stark generational divide, with younger voters under the age of 45 strongly behind Massie and Gallrein winning with older voters, especially those over 65.
Gallrein has cast himself as a loyal team player who would reliably back Trump. In the closing stretch, Massie has stressed that he still votes with Trump roughly 90% of the time, even as his breakaway positions highlight the risk of alienating Kentucky voters loyal to a president who won the state handily in 2024 with 64.5% of the vote.
"This really is a Trump versus Massie race. It has come down to a pick-a-side moment," said Shane Noem, chairman of the Republican Party in Kenton County, which is located in the district.
The other contests on Tuesday could also hold clues on the future direction of the Republican Party heading into November.
In Georgia, Republicans will choose a nominee to take on Democratic Senator Jon Ossoff in November while selecting from a crowded primary for the successor to term‑limited Governor Brian Kemp. In that race, Trump‑backed Lieutenant Governor Burt Jones is among the leading contenders seeking to face a Democratic field led by former Atlanta Mayor Keisha Lance Bottoms.
In Kentucky, Republicans will vote for their nominee to replace longtime Senate leader Mitch McConnell, with U.S. Representative Andy Barr, who secured Trump's endorsement, and Attorney General Daniel Cameron, the leading contenders.
(Reporting by Nathan Layne, editing by Ross Colvin and Deepa Babington)
