Summary (tl;dr)

Incumbent Republican Senator Bill Cassidy of Louisiana was defeated in the recent primary election, failing to secure a spot in the runoff. Fellow Republicans Representative Julia Letlow and State Treasurer John Fleming will now compete in a runoff, an outcome significantly influenced by former President Donald Trump's opposition to Cassidy.

Essential Background

Bill Cassidy, a Republican, has represented Louisiana in the U.S. Senate since 2015, winning re-election for his second term in 2020. His standing within the Republican party was notably challenged when he became one of seven Republican senators to vote to convict former President Donald Trump in his second impeachment trial following the January 6, 2021, Capitol attack. This action led to a censure from Louisiana's Republican party and prompted Trump to actively seek Cassidy's removal from office. Julia Letlow, a Republican, currently serves as the U.S. Representative for Louisiana's 5th Congressional District, having first been elected in a 2021 special election after the tragic death of her husband, Luke Letlow, due to COVID-19 before he could assume office. John Fleming, also a Republican, is the current Louisiana State Treasurer and a former U.S. Representative.

The Full Story

On May 16, 2026, Louisiana held its Republican primary election for the U.S. Senate, which saw a significant upset as incumbent Senator Bill Cassidy was eliminated from the race. Cassidy finished third, garnering 24.4% of the vote, and will not advance to the runoff election. Instead, Representative Julia Letlow, who received a crucial endorsement from former President Donald Trump, led the field with 45.2% of the votes, while State Treasurer John Fleming secured second place with 28.3%. Since neither Letlow nor Fleming achieved more than 50% of the vote, they are now set to face each other in a runoff election scheduled for June 27, 2026. This outcome is largely viewed as a victory for former President Trump, who had strongly campaigned against Senator Cassidy due to his impeachment vote.

Why It Matters

This election result in Louisiana underscores the continued and significant influence of former President Donald Trump within the Republican Party, demonstrating his capacity to shape primary elections, particularly against incumbents he perceives as disloyal. The defeat of Senator Cassidy, a two-term incumbent, highlights the power of Trump's endorsements in swaying voter sentiment and potentially altering the composition of the Republican caucus in the U.S. Senate. The impending runoff between Julia Letlow and John Fleming will ultimately determine Louisiana's next Senator, with the winner of this Republican primary expected to win the general election in the staunchly red state.

Geographic Location

• Louisiana, United States (statewide Republican primary election for U.S. Senate)
• Baton Rouge, East Baton Rouge Parish, Louisiana, United States (election night watch parties and concession speech)