Sen. Bill Cassidy’s primary challengers are projected to advance in a competitive contest for his Louisiana Senate seat — locking the incumbent out of a path forward.

Rep. Julia Letlow, who received President Donald Trump’s endorsement, and state treasurer and former Rep. John Fleming, a MAGA darling, will advance to a runoff for the Republican nomination on June 27, the Associated Press projected Saturday.

Cassidy’s relationship with Trump, whom he voted to convict after the Jan. 6 riot at the Capitol in 2021, has long been tense. And his projected loss gives Trump another win in his revenge campaign against Republicans who crossed him.

“Senator Bill Cassidy of Louisiana is a disloyal disaster,” said Trump in a Truth Social post on Saturday morning. “Bill Cassidy is a sleazebag, a terrible guy, who is BAD FOR LOUISIANA. Now he’s going to get CLOBBERED, hopefully, in today’s BIG election, by two great people!!! VOTE TODAY FOR JULIA L. She Is a winner who will NEVER let you down.”

The senator, a physician, continued to put himself at odds with the president over aspects of his public health agenda during this administration. He criticized Health Secretary Robert F. Kennedy Jr.’s vaccine policies, and Trump blamed him for delaying the nomination of his first surgeon general pick, Dr. Casey Means.

On most other issues, Cassidy aligned himself with the president. And he was still taking a confident posture at the start of Election Day.

“I’m going to win today,” Cassidy told Politico in an interview on Saturday. “I may go into a runoff. But I’m always going to vote for the good of my country and my people.”

This cycle was the first in 50 years that Louisiana used a closed-primary system, meaning moderates like Cassidy could not count on votes from independents and Democrats as they had in recent primaries. Cassidy’s campaign criticized the closed-primary law the day before the election.

“It’s not an accident that voters are confused by this intentionally difficult process,” Katie Larkin, Cassidy’s campaign manager, said in a statement. “The Governor closed the primary and continuously meddled in this election to support Julia Letlow.”

Cassidy’s projected loss will create a vacancy in the Senate next year for his spot as the top Republican on the chamber’s Senate Health, Education, Labor, and Pensions Committee.

Letlow is the latest Trump-backed primary candidate to perform well, even if she’s yet to secure the nomination. Last week, the president’s picks swept in Indiana’s state Senate races, and attention for now will turn to Kentucky’s Fourth Congressional District, where Rep. Thomas Massie hopes to fend off his Trump-backed challenger.

Letlow, a three-term lawmaker, also earned the support of the MAHA movement and its MAHA PAC, which pledged to spend $1 million to elect her. The group spent just under $600,000, according to an FEC report filed in the week leading up to the election.

Gov. Jeff Landry also urged major donors to give to Letlow’s campaign, much to the frustration of other Republicans in the state, Politico reported. In the final weeks of the campaign, she focused on beating Fleming rather than Cassidy. A super PAC supporting Letlow, Accountability Project, spent about 10 times more in ads targeting Fleming than it did targeting Cassidy over the course of the race, according to AdImpact.

Fleming, a founding member of the House Freedom Caucus who worked in the first Trump administration, largely self-funded his campaign. He faced calls to drop out out of fear that he would foil the president’s pick. He told CNN that he received three calls from the White House to drop out before the filing deadline. Trump adviser Alex Bruesewitz posted on X last week that he should drop out.

While the MAGA base didn’t back Cassidy during this primary, top GOP leaders did. Majority Leader John Thune and the National Republican Senatorial Committee gave him their endorsements.

Cassidy’s relationship with the NRSC was at times fraught. Punchbowl News reported in April that Cassidy told the NRSC it was not spending enough on his behalf. The Senate GOP’s super PAC, the Senate Leadership Fund, did not spend in the primary.

Cassidy’s campaign and Louisiana Freedom Fund, a super PAC backing Cassidy, spent nearly $22 million on ads, according to AdImpact. He ran ads that featured Trump, despite not receiving his endorsement.

Of the federal races that appeared on the ballots for Saturday’s primary, only the results for the Senate race will be valid. Landry suspended the House primaries despite voting already being underway so the state could draw a new congressional district after the Supreme Court weakened the Voting Rights Act.

The House primaries have been rescheduled for Nov. 3.