NEW ORLEANS (AP) — When Charles Wandfluh voted in Louisiana's Republican primary over the weekend, he could only conjure the unflattering image of a panicked rodent when talking about Bill Cassidy's desperate attemp t to cling to his U.S. Senate seat despite opposition from President Donald Trump.

"He's just a squirrel running around the tree, chasing nuts to find whatever he can get to benefit him," said Wandfluh, 57, in a suburb of New Orleans.

Cassidy's scramble was in vain, and his defeat on Saturday demonstrated the near-impossibility of a political future within the Republican Party without Trump's acquiescence. Despite outspending his rivals, Cassidy finished third in the primary, falling short of even making a runoff. The outcome was the latest and perhaps most spectacular failure by a Republican who tried to cross Trump and get away with it.

Even within a party notorious for its political contortions during the Trump era, Cassidy stood out. As a doctor, he overlooked Robert F. Kennedy Jr.'s anti-vaccine activism to support his nomination as Trump's health secretary, only inevitably to clash with Kennedy once he took the job.

Cassidy was also unable to repair his relationship with Trump five years after voting to convict him during his impeachment trial over the Jan. 6 attack on the U.S. Capitol. Although Cassidy tried to assure Republican voters that he remained committed to Trump's agenda, that did not satisfy their loyalty to the Republican president.

"He was trying to portray himself side by side with Trump, like he has worked with Trump on this and that," Wandfluh complained. "I'm like, 'You voted to impeach the guy!'"

Trump's endorsed candidate

U.S. Rep. Julia Letlow, endorsed by Trump, and state Treasurer John Fleming, a former Trump administration official, will compete for the Republican nomination on June 27.

"There is no greater endorsement than the endorsement of President Trump," said Letlow, who was first in the voting Saturday. "We'll always be singing that from the mountaintops."

Trump liked what he heard, posting on social media that it was a "great victory speech tonight by Julia!!!" The president stomped on Cassidy's electoral grave, describing the senator as ungrateful for previous support.

"His disloyalty to the man who got him elected is now a part of legend, and it's nice to see that his political career is OVER!" Trump wrote.

U.S. Sen. Lindsey Graham, a South Carolina Republican who feuded with Trump in the past but has since become a model of loyalty to the president, had no sympathy for his vanquished colleague.

"What's the headline? Trump's strong. Those who try to destroy Trump politically, stand in the way of his agenda, are going to lose," Graham said Sunday on NBC's "Meet the Press." "You can disagree with President Trump, but if you try to destroy him, you're going to lose. Because this is the party of Donald Trump."

Purging the party

Graham once described Trump as a "kook" who was "unfit for office," and he appeared to break with Trump after the Jan. 6 riot by saying "enough is enough." But Graham did not vote to convict Trump during the impeachment trial, unlike Cassidy and six other Republican senators.

Four of them — Richard Burr of North Carolina, Mitt Romney of Utah, Ben Sasse of Nebraska and Pat Toomey of Pennsylvania — did not run for another term afterward.

Alaska's Lisa Murkowski, who remains in office and is a vocal Trump skeptic, won reelection in 2022 when Trump was out of office. There also is Maine's Susan Collins, who has faced Trump's wrath but not a primary challenge as she runs for a sixth term in November. As a Republican senator from a state won by Democratic candidate Kamala Harris in the last presidential election, she remains crucial for her party's control of Congress.

Trump's grip on his party is noteworthy given his lame-duck status — he is constitutionally prohibited from running for a third term even though he has mused about it — and his low poll numbers. He is presiding over lingering inflation, economic dissatisfaction and an unpopular war with Iran, yet Republicans remain largely in lockstep with him.

As he approaches the back half of his second term, Trump appears to be finalizing a wholesale makeover of the party that he began a decade ago, and his appetite for retribution does not appear to be waning.

Earlier this month, he successfully dislodged five Indiana state senators who opposed his redistricting plan. On Tuesday, he is backing a challenger to U.S. Rep. Thomas Massie in Kentucky's primary. Massie angered Trump by opposing his signature tax legislation over concerns about the national debt, pushing for the release of the Jeffrey Epstein files and opposing his decision to go to war with Iran.

Over the weekend, Trump suggested that he could next target U.S. Rep. Lauren Boebert of Colorado because of her support for Massie.

"Even though I long ago endorsed Boebert, if the right person came along, it would be my Honor to withdraw that Endorsement, and endorse a good and proper alternative," Trump said, although the filing deadline for Colorado candidates passed months ago.

All about Trump

After his defeat, Cassidy addressed Trump's influence without naming him.

"Our country is not about one individual. It is about the welfare of all Americans, and it is about our Constitution," the senator told supporters in Baton Rouge. "And it is the welfare of my people, and my state, and my country, and our Constitution to which I am loyal."

But Trump's role was central for many Republican voters.

Mark Schulingkanp, who is 46 and works in the shipping industry, said he voted for Letlow precisely to avoid the conflict that has marked Cassidy's relationship with Trump.

"Getting federal dollars into the state is the most important thing to me, to help people with jobs," he said. "Clearly having a senator that the president doesn't like could cause a challenge or impede federal dollars coming to the state for roads, bridges, so many different programs."

Jeanelle Chachere, a 66-year-old nurse, described Cassidy as a "phony" and said she voted for Letlow solely because of Trump's endorsement.

"I'm going by what he says because I like what he does," she said.

In a sign of how Cassidy had backed himself into a political corner, he also lost support in some quarters for going along with Trump's demands.

Mark Workman, a 75-year-old retired physician, said he voted for Fleming to punish Cassidy for backing Kennedy's confirmation.

"If Cassidy had stood up and blocked RFK, I would definitely have supported him because that would have been a strong, ballsy move," Workman said. "He had the ability to stop him and he was too weak to do that."

Beaumont reported from Des Moines, Iowa. Associated Press writer Bill Barrow in Atlanta contributed to this report.