Letlow wins Louisiana GOP runoff for Cassidy Senate seat

Julia Letlow defeated John Fleming in Louisiana’s Republican Senate runoff, moving to the November 3 general election for the U.S. Senate seat now held by Bill Cassidy. The race was the latest test of where Republican politics in the state now sit after Cassidy’s break with Donald Trump.

Letlow entered the runoff with the edge she built in the May 16 primary, when she finished first with about 45% of the vote. Fleming followed with about 28%, while Cassidy, who was seeking a third term, finished third with roughly 24% to 25% and failed to make the runoff. That result pushed one of the cycle’s most closely watched incumbent defeats into a two-candidate contest and left Cassidy on the outside of the general election field.

Trump’s endorsement of Letlow gave the race a clear line of divide. Cassidy had become a Trump target after voting to convict him in the 2021 impeachment trial, and the runoff turned into a measure of how much that clash still matters to Republican voters in Louisiana. Letlow’s victory suggested that, inside the state party, allegiance to Trump remains the stronger force than Cassidy’s seniority or institutional standing in Washington.

The numbers from the primary point to a party still organized around Trump’s base. Letlow’s 45% placed her far ahead of Fleming and Cassidy, showing that a Trump-backed candidate could consolidate the dominant share of Republican voters even in a crowded field. Louisiana’s electorate reinforced that dynamic in 2024, when Trump won 60% of the vote in the state, and the state has not elected a Democrat to the Senate since 2008.

Cassidy’s loss also marked a sharp break from the recent history of Senate incumbents. His third-place finish made him the first incumbent senator to lose a primary since 2012, a reminder that even in a state where Republicans hold the advantage, an incumbent can be swept aside when the party’s internal loyalties shift.

The Republican runoff took place alongside a Democratic runoff for the same seat, but the November election is expected to settle the contest for Louisiana’s Senate seat. Letlow now heads into that race as the candidate most aligned with the state party’s current center of gravity, where Trump loyalty and partisan discipline appear to have eclipsed Cassidy’s old coalition.