Sen. Bill Cassidy of Louisiana lost his Republican primary bid for reelection Saturday, becoming the most prominent Senate Republican to be ousted after breaking with former President Donald Trump. Cassidy, who voted to convict Trump during his second impeachment trial in 2021, was defeated by challengers backed by Trump, with Rep. Julia Letlow and John Fleming advancing to a runoff to compete for his seat.

The result was widely anticipated after Trump made Cassidy's defeat a priority, endorsing candidates to replace him and campaigning against the incumbent senator. Cassidy had been one of only seven Republican senators to vote for conviction following the January 6, 2021 Capitol riot, a position that made him a long-standing target within the party's Louisiana base.

Letlow, a congresswoman from Louisiana's 5th District, was among the top vote-getters in the primary field, alongside Fleming, a former congressman. Because no candidate secured a majority, the two will face each other in a runoff election to determine who will claim the seat Cassidy has held since 2015.

The outcome drew immediate attention as a signal of Trump's continued grip on Republican primary politics heading into the 2026 midterm cycle. Cassidy's loss reinforced a pattern in which Republicans who voted to impeach or convict Trump have faced significant political consequences within the party, with several either losing primaries or opting not to seek reelection.

Cassidy had defended his impeachment vote as a matter of conscience and constitutional duty, and made his reelection bid despite long odds in a state where Trump remains deeply popular. His defeat leaves no Republican senator who voted to convict Trump currently seeking reelection on the primary ballot without facing a stiff challenge from Trump-aligned opponents.