Letlow advances to Louisiana GOP Senate runoff as Cassidy fights for survival

Julia Letlow surged into Louisiana’s Republican Senate runoff, while Bill Cassidy and John Fleming were left fighting for the second slot in a June 27 contest that has become a test of Donald Trump’s grip on the state party.

NBC News projected on May 16 that Letlow would advance after no candidate reached a majority in the GOP primary. Letlow, who entered the race with Trump’s endorsement, held a wide lead over Fleming and the incumbent senator, underscoring how quickly the race has shifted from a standard re-election fight into a referendum on who defines Louisiana Republicans now.

Cassidy’s vulnerability carries unusual weight because this is his first primary since he voted in 2021 to convict Trump in the former president’s second impeachment trial after the Jan. 6 attack on the Capitol. Trump has singled him out as one of the few remaining Republican senators who broke with him on that vote, and later called Cassidy a “disloyal disaster” on Truth Social. Cassidy has argued that his record on infrastructure and health care merits another term, but Letlow’s entry gave the anti-Cassidy bloc its most serious opening yet.

The stakes extend beyond one Senate seat. If Cassidy is defeated, it would mark the first time in more than a decade that an elected Senate incumbent lost renomination, a sign of how much the party’s internal loyalty tests now matter. Letlow’s rise, paired with Cassidy’s struggles, suggests that Trump-aligned candidates can still dominate in Louisiana even when they challenge established officeholders, while a once-safe incumbent can suddenly look exposed.

The race is unfolding under Louisiana’s new closed Republican primary system for certain offices, including U.S. Senate, a change that can affect who is allowed to vote and has already raised concerns about confusion at the polls. Louisiana officials delayed House primaries after a U.S. Supreme Court ruling on congressional maps, but the Senate race stayed on schedule. That contrast has made the Senate contest one of the clearest examples of how election rules, party loyalty, and national Republican fractures are colliding in Louisiana.

The winner of the GOP runoff will be heavily favored in November, with Louisiana’s deep Republican lean and Trump’s more than 60% share of the state vote in 2024. For now, though, the fight is less about the general election than about which wing of the Republican Party gets to claim Louisiana’s biggest prize.