In the 2026 Louisiana Republican Senate primary, incumbent Senator Bill Cassidy failed to secure enough support to reach the runoff, marking a significant political setback.

Cassidy, who faced criticism from former President Donald Trump for voting to convict him during his second impeachment related to the January 6, 2021, Capitol attack, received just over 24 percent of the vote.

Representative Julia Letlow led the race with over 40 percent, while Louisiana State Treasurer John Fleming claimed the second spot with nearly 30 percent, setting up a runoff between Letlow and Fleming on June 27.

Cassidy's elimination reflects the continuing influence of Trump-backed candidates within the GOP and highlights the challenges faced by incumbents who opposed Trump in key votes.

The primary outcome is being closely watched as an indicator of Republican voter sentiment heading into the 2026 midterms, particularly in high-profile Senate contests where loyalty to Trump remains a decisive factor.The runoff will determine which candidate represents the GOP in the general election for this critical Senate seat.