Trump's Endorsement Power on Display as Louisiana Ousts Cassidy

Senator Bill Cassidy of Louisiana learned a hard lesson about the currency of loyalty in modern Republican politics. Five and a half years after he voted to convict Donald Trump during the first impeachment trial, Cassidy faced the voters of his home state on Saturday—and they rejected him. Two Trump-backed candidates, Representative Julia Letlow and Louisiana Treasurer John Fleming, finished ahead of him in the GOP primary, sending Cassidy toward a runoff he will not win. He became the first elected Republican senator to lose renomination since Richard Lugar of Indiana in 2012.

The primary was a referendum on Trump's grip over the Republican Party, and the results were unambiguous. Letlow, whom Trump encouraged to enter the race in January and then endorsed completely, spoke of his backing as "the honor of a lifetime." She called it "the most powerful endorsement in the world," and in a state Trump carried by 22 points in 2024, that assessment held weight. Governor Jeff Landry, a Trump ally, also backed her. Fleming, who served as a White House deputy chief of staff during Trump's first term, positioned himself as the true MAGA candidate, claiming Letlow was "much more like a Democrat" and not the prototype for a Trump endorsement.

Cassidy had tried to build a different case. He highlighted his record across two Senate terms, pointing to four bills he had written or negotiated that Trump signed into law. He emphasized his work for Louisiana, a state among the poorest in the nation, and his support for the oil and gas industry, which employs roughly 15 percent of the state's workforce. He spent lavishly to make his case—more than $20 million on advertising through his campaign and allied super PAC, a sum that exceeded what Letlow and Fleming spent combined. Some of those ads attacked Letlow over her past support for diversity, equity and inclusion programs during her time at the University of Louisiana at Monroe. Cassidy argued that voters were "concerned about her shifting position on DEI."

But money and legislative accomplishment proved insufficient against the weight of Trump's disfavor. The senator's original sin—voting to convict Trump in early 2021 for his role in the January 6 Capitol attack—had never been forgiven, even as Cassidy moved to support the president's agenda and nominees in Trump's second term. He voted to confirm Robert F. Kennedy Jr. as Health Secretary, yet that gesture could not overcome the enmity of Kennedy's allies. Kennedy and his Make America Healthy Again movement had their own reasons to oppose Cassidy. As a physician and chair of the Senate Health, Education, Labor, and Pensions Committee, Cassidy had been skeptical of Kennedy's health policy reforms, particularly his efforts to reduce vaccine recommendations. Kennedy allies blamed Cassidy for blocking the surgeon general nomination of Casey Means, a Kennedy confidant and MAHA advocate, after Cassidy declined to bring the nomination to a committee vote. Trump, meanwhile, called Cassidy a "very disloyal person" and praised Letlow as a "Highly Respected America First Congresswoman."

Letlow faced her own vulnerabilities. She had failed to disclose more than 200 personal stock and bond trades within the mandated 45-day reporting window required of members of Congress. She attributed the lapse to "a reporting error on my financial advisor's part" and said she remedied it immediately. She also had to defend her earlier support for DEI initiatives, explaining that when the concept was introduced in 2020, she did not understand what it was, but once she witnessed "the left completely hijack it, turn it into this Marxist leftist indoctrination," she began fighting against it in Congress. She dismissed the attacks from Cassidy and Fleming as "all baseless attacks, desperate attacks."

Letlow had arrived in Congress through tragedy. She won her seat in 2021 after her husband, Luke Letlow, died six days after being sworn in following his own 2020 election victory for that same seat. Now she was advancing to a runoff against Fleming, with the winner nearly certain to hold the seat in the general election. The primary had delivered its message: in the Republican Party of 2026, Trump's endorsement remained the most valuable commodity on offer, capable of overcoming a sitting senator's legislative record, financial advantage, and institutional position. Cassidy's defeat was not a personal failure but a structural one—a sign of how thoroughly the party had reorganized itself around a single figure's preferences.