Louisiana GOP Senate Runoff Tests Trump's Endorsement Power

If you've been paying attention to how much sway Donald Trump still holds over his own party, Louisiana just gave you a pretty clear answer.

On Saturday, June 28, 2026, Rep. Julia Letlow won Louisiana's Republican Senate runoff, defeating state Treasurer John Fleming and cementing another victory for Trump's endorsement machine. The race was to fill the seat of outgoing Sen. Bill Cassidy — and the backstory here is almost as interesting as the result.

How We Got Here

Cassidy, a two-term Republican senator, had been on thin ice with Trump ever since he voted to convict the president during his second impeachment trial following January 6th. Trump didn't forget. When Louisiana's Senate race kicked off, Trump endorsed Letlow before she'd even officially announced she was running — and spent months calling Cassidy a "disloyal disaster." The strategy worked: in the May 16 primary, Cassidy finished a humiliating third with about 25% of the vote, while Letlow led with 45% and Fleming came in second at 28%. Because no one hit 50%, Letlow and Fleming went to a runoff — and Cassidy was done. He became the first elected incumbent senator to lose renomination since Richard Lugar back in 2012.

The Runoff: Two Trump Allies, One Endorsement

Here's where it gets interesting. This wasn't a MAGA-vs.-moderate race. Both Letlow and Fleming were running as staunch Trump supporters. Fleming — a former congressman and Trump White House veteran — argued he was the "real" MAGA candidate, pointing to his long history with the movement. He even claimed Trump called him "fantastic" in a private phone call, despite not getting the official endorsement.

But Trump stuck with Letlow. The night before the vote, he held a phone rally for her, calling her a "Total Winner" and a "Great Star." He praised her vote for his tax bill, her support for his immigration agenda, and her backing of his push to overhaul U.S. elections. With Trump's backing also came Louisiana Gov. Jeff Landry and House Majority Leader Steve Scalise.

Fleming tried to hit Letlow on a vulnerable spot: her past support for DEI (diversity, equity, and inclusion) policies when she was a university administrator. Letlow said she had since reversed course once she "saw it for what it was."

On the money side, Fleming actually outspent Letlow — loaning himself more than $11 million and raising over $12 million total — but a super PAC backing Letlow spent about $4 million in the runoff alone, giving her a real air-war advantage.

The Result and What It Means

Letlow won 57%-43%. It wasn't as nail-bitingly close as some had predicted. The AP called it just 44 minutes after polls closed.

For Trump, this is a meaningful rebound. Earlier in June, GOP voters in Iowa and Georgia ignored his picks in gubernatorial races — a rare public snub. This win lets him point to Louisiana as proof his endorsement still moves Republican primary voters.

For you personally? If you care about the direction of the Senate, this race matters. Letlow is all but certain to win the general election in November — Louisiana hasn't sent a Democrat to the Senate since 2008, and Trump carried the state by more than 18 points in 2024. She's pledged to support Trump's agenda, including his push to eliminate the Senate filibuster for his elections bill. That's the kind of vote that shapes national policy well beyond Louisiana's borders.