Last night, Donald Trump notched the latest victory in his cross-country revenge campaign against political apostates. Ed Gallrein, a Navy SEAL backed by the president, soundly defeated the seven-term representative Thomas Massie in Kentucky’s Fourth Congressional District. The 10-point drubbing followed the triumphs of other Trump-tapped challengers in primaries in Louisiana and Indiana, which effectively ended the careers of local legislators and a sitting U.S. senator who had angered the president.“This is basic political management of a party,” a senior White House adviser said yesterday, before the Kentucky contest. “You have to keep everybody on the reservation. Occasionally you have to shoot a hostage. The next one is Thomas Massie.” Less than two hours after polls closed, Gallrein was projected as the winner.Gallrein has an illustrious military résumé, but he has never held elected office and barely campaigned for this one, skipping every debate with Massie. What Gallrein did have was Trump’s endorsement, and that was all that mattered.This decisive outcome underscores what should already have been obvious: Even as Trump’s overall approval rating hits new lows, his hold on the Republican Party—and specifically its MAGA core—remains absolute. Contrary to months of breathless headlines, the president’s base never deserted him and continues to punish those who defy him. That’s because the MAGA movement is united, not by any particular set of ideological commitments but by commitment to a particular person.[Russell Berman: Why Thomas Massie thought he was different]Gallrein’s final online ad was just 15 seconds long, and he never said a word in it. “This is a real hero,” intoned a Trump voice-over. “Ed Gallrein has my complete and total endorsement.” In a video filmed in the Oval Office and posted on the eve of the election, Trump was more explicit about what was really at stake in this clash. “Ed Gallrein, he’s fantastic,” the president declared. “But forget that. Massie is the worst congressman in the history of our country, always voting against Republicans and good values. So get rid of Thomas Massie.” The next day, Republican voters obliged, and the Kentucky representative joined the ranks of Senator Bill Cassidy of Louisiana and Representative Marjorie Taylor Greene of Georgia as recent casualties of Trump’s perpetual purge of the insufficiently subservient.That list of victims is long and dates back to Trump’s first term. It includes nearly all GOP members of Congress who voted to impeach the president, as well as the chairman of the House Freedom Caucus, who had the temerity to endorse Ron DeSantis over Trump in 2024. These people were drummed out of politics not because of their ideologies—some were establishment squishes, others hard-right gadflies—but because they violated the one real rule of the MAGA Republican Party: Never cross the boss.Massie allied with Democrats to oppose Trump’s Middle East policy and his handling of the Epstein files, and voted against Trump’s signature tax-and-immigration bill. Louisiana’s Cassidy voted to convict Trump after the January 6 riot. Indiana’s local Republicans refused to redistrict the state according to the president’s wishes. What united—and doomed—all of these soon-to-be-former legislators was not their politics but their refusal to fall in line.This dynamic also explains why none of Massie’s ideological attempts to defend his seat made a difference. As the tide turned against him, Massie leaned into anti-Israel advocacy as his closing argument. He told a reporter that if he lost, it would mean that “Israel controls this Congress,” and joked that his opponent’s phone number had an area code “in Tel Aviv,” a line he repeated in his concession speech last night.He also openly engaged with anti-Semitic ideas and influencers. The weekend before the election, Massie invited a select group of supporters to his homestead in northeastern Kentucky, including the Holocaust denier Ryan Matta, who previously posed for a photo with Massie and hugged him while wearing an American Reich shirt. At the gathering, Massie played guitar alongside David Reilly, an activist who has described himself as an “anti-Semite.” In the final days of the campaign, a pro-Massie PAC ran an ad that superimposed a rainbow Star of David behind an image of Paul Singer, a conservative pro-Israel donor known to support LGBTQ causes. It warned that the ultraconservative Gallrein would bring “trans madness” to Kentucky at the Jewish donor’s behest: “The gay mafia will own Eddie.”But whatever one thinks of Massie’s anti-Israel activism and anti-Jewish insinuations, neither was the reason he was excised. A libertarian opponent of all foreign aid, Massie voted year after year against assistance to Israel with little consequence. The White House began plotting his ouster only after he voted against Trump’s “big, beautiful bill” in May 2025. The Israel-critical Massie committed the same sin that prompted Trump to defenestrate the Israel hawk Liz Cheney: He defied a president who prized personal loyalty above all else and was punished by a GOP electorate that enforced their leader’s litmus test.[Yair Rosenberg: The biggest myth about Trump’s base (and why many believe it)]Massie and his allies knew that his break with Trump was his real liability, whether they admitted it or not. They ran ads emphasizing Massie’s alignment with the president and others accusing Gallrein of being a “Trump hater” and “Trump traitor.” On Election Day, the campaign sent a text message to voters touting Trump’s endorsement of Massie in 2022—with the date removed. This prompted Trump to return to X for the first time in months to demand that Massie disavow the ruse.Massie did not. But his campaign’s desperation to deceive the electorate into thinking that he was actually allied with the president illustrates why he lost before the fight began: Even Massie’s own advertising accepted the premise of the case against him. Pro-Trump and pro-Israel groups poured millions into the race against Massie, but the ads they aired worked only because Republican primary voters were primed to accept their argument that those disloyal to Trump had to go.That the current Republican Party is defined by allegiance to a person rather than any principle is not a new development. “America First” has always meant Trump first. “All this time, I thought they were voting for libertarian Republicans,” one astute Republican congressman mused to the Washington Examiner as far back as 2017, “but after some soul searching I realized when they voted for Rand and Ron [Paul] and me in these primaries, they weren’t voting for libertarian ideas—they were voting for the craziest son of a bitch in the race. And Donald Trump won best in class, as we had up until he came along.”The politician who said that was Thomas Massie.