Defense Secretary Pete Hegseth stood at a campaign rally in Kentucky on Monday and made the case for removing a sitting Republican congressman, not a Democrat, but one of the GOP's own. The target: Rep. Thomas Massie, a seven-term libertarian-leaning conservative whose refusal to fall in line on key votes has made him the subject of what is now the most expensive House primary in American history.
As of Monday, at least $32.6 million had poured into political advertising for the Republican primary in Kentucky's Fourth Congressional District, the New York Post reported, citing figures from ad-tracking firm AdImpact. The challenger, Trump-endorsed retired Navy SEAL Ed Gallrein, has spent nearly $11 million. Massie has spent $7.6 million. The rest, millions more, has come from outside groups on both sides.
The sheer scale of spending tells the story of a party at war with itself over what loyalty means and who gets to define it.
President Trump posted a blistering message on Truth Social on Monday, calling Massie "the worst Congressman in the long and storied history of the Republican Party." He added:
"He is an obstructionist and a fool. Vote him out of office tomorrow, Tuesday. It will be a great day for America!"
Trump had endorsed Gallrein last October, calling the retired Navy captain "a true America First Patriot" and describing him as "central casting." But the president's involvement has gone well beyond a standard endorsement. His 2024 co-campaign manager, Chris LaCivita, and pollster Tony Fabrizio took charge of a Kentucky MAGA super PAC last year with the explicit goal of taking Massie down.
Trump also personally recruited Gallrein for the race, Newsmax reported, after the congressman repeatedly voted against key administration priorities. The president posted a video to Truth Social saying he hoped Kentucky voters would put Massie "out of business."
The effort follows a pattern. Just days earlier, Sen. Bill Cassidy of Louisiana fell to Trump-backed Rep. Julia Letlow in his own primary. And earlier this cycle, Trump-endorsed challengers swept Indiana's GOP primaries, punishing incumbents who had crossed the president on redistricting.
The appearance of a sitting defense secretary at a congressional primary rally was unusual by any standard. Hegseth, who campaigned for Gallrein the night before the vote, framed the race in stark terms.
"President Trump does not need more people in Washington who are trying to make a point, especially from his own party. He needs people willing to help him win, to vote with him."
Breitbart reported that Hegseth also told the rally crowd, "President Trump needs reinforcements, and that's what war fighters do." He added a pointed jab at Massie's record: "At some point, being against everything becomes an excuse for accomplishing nothing."
Gallrein's military credentials are formidable. He served multiple combat deployments and received four Bronze Stars for valor. But his political biography has drawn scrutiny. A pro-Massie PAC highlighted that Gallrein shifted his party affiliation to independent after Trump's 2016 election and only changed his registration back when Joe Biden was in the White House.
The case against Massie centers on a handful of high-profile breaks with the Republican majority. He refused to support the One Big Beautiful Bill Act, declined to help pass certain funding measures during shutdown showdowns, and has been a vocal critic of deeper U.S. involvement in Iran.
But Massie's supporters point out that his dissent is principled, not partisan. AP News reported that Massie told voters they did not have to choose between Trump and him, arguing that his breaks with the party were on issues that violated his "America First principles."
The Epstein files dispute has become one of the most combustible elements of the race. Massie co-authored legislation that forced the Department of Justice to release investigative materials on the prosecutions of Jeffrey Epstein and his accomplice Ghislaine Maxwell. He helped generate enough support, with a handful of Republicans and most Democrats, to push it through Congress. Trump signed the bill into law one month after endorsing Gallrein.
The DOJ eventually released more than 3 million pages of documents and tens of thousands of photos and videos. A prior review, completed by the DOJ and FBI in July 2025, determined that Epstein never blackmailed any of his associates and that no third parties could be charged in connection with his sex crimes. Epstein had committed suicide on August 10, 2019, while awaiting trial on sex trafficking charges.
Massie has framed the race as partly about foreign-policy influence, calling it "a referendum on whether Israel gets to buy seats in Congress." Pro-Israel groups including AIPAC and the Republican Jewish Coalition have funneled contributions to Gallrein's effort. Tensions between Trump, Massie, and his allies have escalated over the Epstein files and related policy disputes for months.
Nearly $8 million funded attack ads targeting Massie, while more than $6 million went toward attack ads against Gallrein. The airwaves in northern Kentucky have been saturated for weeks.
One ad drew particular controversy: an AI-generated spot that placed Massie alongside Democratic Reps. Ilhan Omar and Alexandria Ocasio-Cortez. Massie called the ad "defamatory." Former Rep. Marjorie Taylor Greene, who has supported Massie, argued the AI attack ad violated the TAKE IT DOWN Act.
Greene is not the only Republican who has backed Massie against the Trump operation. Rep. Lauren Boebert of Colorado, Rep. Victoria Spartz of Indiana, and Sen. Rand Paul of Kentucky have all supported the incumbent. Boebert traveled to Kentucky to campaign for Massie in the final stretch.
Trump, for his part, has not taken kindly to Republican defectors. He previously lashed out at Massie in 2020, calling him a "third-rate Grandstander" for opposing a $2 trillion COVID-19 stimulus package. The grudge, it appears, never faded.
For all the money and firepower deployed against Massie, the race remains extraordinarily close. A May 15 public survey from Big Data Poll found Massie leading Gallrein 50.6 percent to 49.4 percent, within any reasonable margin of error.
Nearly $20 million in outside spending from lobbying groups, allied PACs, and national Republican organizations has gone into trying to defeat Massie, Fox News reported. The contest has become what multiple outlets describe as a national proxy fight over Trump's control of the Republican Party, the direction of foreign policy, and whether dissent within the GOP is still permitted.
The result, as Cassidy's loss in Louisiana already suggested, will send a signal far beyond Kentucky. If Massie survives $32.6 million in ad spending, a presidential endorsement of his opponent, and a defense secretary campaigning against him, it will be the most expensive repudiation of party leadership in modern primary history. If he loses, the message to every Republican in Congress will be unmistakable.
Thirty-two million dollars to settle a family argument. Whatever the result, Kentucky voters are the ones who get the final word, and the rest of the party will be watching to see what that word costs.