With just two days until the next stress test of Donald Trump’s iron grip on his party, the president spent Sunday waging a one-man war on Truth Social against his favorite Republican punching bag, Thomas Massie. Over an eight-hour period starting in the wee hours, Trump called the Kentucky congressman the “worst and most unreliable Republican Congressman in the history of our Country” and urged voters to “vote the bum out on Tuesday.”

Massie, one of the few senior Republicans who still dares to defy Trump, has been a consistent thorn in the president’s side - voting against his tax and spending cuts, pushing for the release of the Jeffrey Epstein files, and insisting Congress have a say on military actions in Venezuela and Iran. Now he faces a primary challenge from Trump-endorsed Ed Gallrein, a farmer and retired Navy SEAL. Undeterred, Massie went on ABC News’s This Week and declared, “I’m the only one they haven’t been able to bully,” adding that he’s ahead in the polls and Trump is “desperate.” An independent Quantus Insights poll tells a different story: Gallrein leads 48% to 43%, with 8% undecided.

Massie insisted on CNN he’s buoyed by anti-abortion and gun rights groups and grassroots donations, blaming super-wealthy donors like Miriam Adelson and Paul Singer - and what he called the “Israeli lobby” - for flooding Kentucky with cash to unseat him. But the political winds are firmly at Trump’s back. On Saturday, Louisiana Senator Bill Cassidy was ousted in a primary for voting to convict Trump in his 2021 impeachment over the January 6 insurrection. Cassidy’s ejection leaves only two of the seven Republican senators who convicted Trump still in office: Susan Collins in Maine and Lisa Murkowski in Alaska. Only one of the 10 House Republicans who voted to impeach Trump is still running for re-election: David Valadao of California.

Lindsey Graham summed it up on NBC’s Meet the Press: “Bill Cassidy lost because he tried to destroy Trump, Massie is going to lose because he tried to destroy the agenda. If you try and destroy him, you are going to get destroyed.” House Speaker Mike Johnson, speaking on Fox News Sunday, couched the same threat in fluffier language, saying Trump wields “the most powerful endorsement in the history of politics.”

Trump’s iron-fisted control over his party, however, stands in stark contrast to his overall standing with the American people. A new CBS News poll shows approval of Trump’s handling of inflation among Republicans has dropped from 74% in March to 63%, and 70% of all respondents said they’re frustrated or angry with his approach to the economy. Pete Buttigieg, the former transportation secretary and possible 2028 contender, told CNN’s State of the Union he sees a “big opening for Democrats,” noting that under Trump’s control, “the Republican party is organized less and less around conservative principles, more and more around one man.”