Two-term incumbent U.S. Senator Bill Cassidy lost his reelection bid in the Louisiana Republican primary on Saturday. U.S. Congresswoman Julia Letlow and State Treasurer John Fleming officially advanced to a June 27 runoff, eliminating Cassidy from the race.
The defeat occurred amidst deep national Republican divisions over economic frustrations and the ongoing Iran conflict, exposing a persistent five-year intra-party feud within the state.
Major outlets including CNN and NBC News issued live projections early Sunday confirming Cassidy’s exit. Final polling trajectory data from RealClearPolling showed Letlow leading the field with 33.5 percent of the vote, followed by Fleming at 25 percent. Cassidy finished in third place with 22 percent.
According to a detailed report from the Associated Press confirming the runoff, Letlow and Fleming will now face each other next month to determine the Republican nominee.
The structural reason for Cassidy’s vulnerability was a recent election law change. Louisiana Governor Jeff Landry dismantled the state’s traditional open “jungle primary” system this year. The shift to a strict closed primary restricted the electorate exclusively to registered Republicans, removing the moderate and crossover voters Cassidy relied upon for his past victories.
Trump’s involvement played a direct role in the outcome. Cassidy was one of only seven Republican senators who voted to impeach Donald Trump in 2021. In retaliation, Trump heavily recruited and endorsed Letlow.
Trump reacted to the projections Saturday night on Truth Social. “Congratulations to Congresswoman Julia Letlow on a fantastic race, beating an Incumbent Senator by Record Setting Numbers,” Trump posted. He addressed Cassidy directly in a second post, stating, “His disloyalty to the man who got him elected is now a part of legend, and it’s nice to see that his political career is OVER !”
Cassidy’s elimination concludes a multi-year effort by Trump-aligned factions to unseat the remaining Senate Republicans who supported his second impeachment. The enforcement of a closed primary system provides a clear blueprint for conservative challengers looking to defeat moderate incumbents in states that still allow crossover voting. With Letlow and Fleming heading to the runoff, the June 27 election will test whether the establishment wing of the state party can consolidate behind the state treasurer or if Trump’s endorsement guarantees Letlow the nomination.