LOUISIANA — Republican Senator Bill Cassidy faces a primary challenge in Louisiana on Thursday as he seeks renomination to his Senate seat. The winner of the Republican primary is expected to win the general election in the state.

Cassidy, a physician, broke from his party to vote in favor of convicting Donald Trump in impeachment proceedings during Trump's first term, joining seven other Republican senators in voting to convict him of incitement of insurrection following the January 6, 2021 storming of the U.S. Capitol by Trump supporters. The Senate did not reach the two-thirds majority needed to convict, and Trump was acquitted.

Trump has endorsed U.S. Representative Julia Letlow in the race. State Treasurer John Fleming is also running in the primary. Polls have shown Cassidy trailing both Letlow and Fleming.

"You shouldn't have to wonder how our senator will vote when the pressure is on," Letlow said in her campaign launch video. Letlow, an academic administrator, entered office in 2021.

In April 2026, Trump accused Cassidy of tanking his nominee for surgeon-general, Casey Means, because of her vaccine skepticism and unproven wellness theories. Trump used the phrase "intransigence and political games" in reference to the senator. "Republicans will be voting Bill Cassidy OUT OF OFFICE in the upcoming Republican Primary!" Trump said.

During Trump's second term, Cassidy regularly touted administration policy initiatives and appeared with Trump at the White House for healthcare-focused events and bill signings. Cassidy has said Letlow lacks conservative bona fides, pointing to her past support of education diversity initiatives, which she has disavowed, and her attendance at the 2023 United Nations climate change conference.

Most Republican senators who voted to convict Trump in 2021 have since left office or been ousted. Republican Senator Susan Collins voted to convict and has not faced major intra-party fallout, while Republican Senator Lisa Murkowski defeated a Trump-backed challenger in her 2022 primary.

Trump carried Louisiana in the 2016 and 2020 presidential elections with about 58 percent of the vote, and in 2024 with 60 percent. At the end of April 2026, his national approval rating was 34 percent. Early primary votes have shown that Trump's endorsement continues to influence voters.

If no candidate wins a majority on Thursday, the race will move to a run-off on June 27. Louisiana has moved through several competitive primary cycles in recent years, with Trump-backed candidates playing a central role in Senate contests.