A new Senate healthcare head is in the cards for 2027 after Louisiana Republican Sen. Bill Cassidy, M.D., failed to advance in his primary over the weekend.
Cassidy is a gastroenterologist who chairs the Senate Health, Education, Labor and Pensions (HELP) Committee and is a member of the Committee on Finance’s Subcommittee on Health Care. He’s held his senate seat since 2015 and served in the House of Representatives during the years prior.
His post has granted a leading role in the confirmation process of the Trump administration’s healthcare appointees, most notably last year when he cast the deciding vote for then Health and Human Services Secretary Nominee Robert F. Kennedy Jr. He did so despite misgivings over Kennedy’s history of vaccine skepticism and has since clashed with the secretary over recommendations related to at-birth hepatitis B vaccination—a public health strategy Cassidy promoted even prior to entering politics—and staffing upheaval at public health agencies like the Centers for Disease Control and Prevention (CDC).
More recently, Cassidy and other moderate HELP Republicans’ concerns stalled out the administration’s bid for another prominent Make America Healthy Again figure, Casey Means, M.D., to become surgeon general. And even as a lame duck, Cassidy remains in control of the confirmation pathway for an unusually large number of government healthcare leadership vacancies: the attorney general, the director of the CDC and, most recently, the commissioner of the Food and Drug Administration (FDA).
The senator’s pushback has drawn the ire of the MAHA movement and joins a longstanding grudge held by President Donald Trump over Cassidy’s historical vote to impeach in 2021 following the January 6 Capitol riots. Cassidy had publicly looked to diffuse the tensions by supporting others major areas of their agendas, such as nutrition or a crackdown on gender-affirming care, but to little political avail. MAHA funders put their money behind challenger Julia Letlow, a current House representative who was encouraged to run and later endorsed by the president.
Saturday’s closed primary—highly watched as a bellwether for Trump’s control over upcoming Republican primaries—showed Letlow as the clear leader with about 45% of the vote, followed by state treasurer John Fleming at 28%. The two will advance to a runoff, while Cassidy’s 25% support prompted his concession.
“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!” Trump wrote Saturday evening in a social media post, another of which congratulated Letlow.
“I will continue [to use] my time in the Senate … making healthcare and health insurance more affordable,” Cassidy said in a concession speech that included numerous jabs at the president’s leadership and conduct.
Whereas Cassidy’s public comments in Senate sessions and the campaign trail have looked to soothe the rift between MAHA and Trump, the primary loss raises the possibility that he will close out the term more vocal on his areas of disagreement with the administration—namely, Kennedy’s push to transform the childhood vaccine schedule. Confirmation hearings or votes could also be held off the HELP Committee’s docket.
Further, the results put a question mark on Cassidy’s ongoing legislative and policy work, which has broached some of the less public-facing mechanisms of the healthcare system.
For instance, Cassidy has headlined investigations into the 340B drug discount program, called for sweeping reforms of the FDA and has been questioning the American Medical Association over its “abusing” of the proprietary Current Procedural Terminology (CPT) coding system. He’s been leading a push to reduce the Affordable Care Act coverage burden by more heavily funding consumer Health Savings Accounts (HSAs) and released a framework for strengthened health data privacy.
There’s also the question of who will replace Cassidy as HELP chair or ranking member come January.
Sen. Rand Paul, M.D., R-Kentucky, would be next in terms of seniority but already serves as chair of the Homeland Security and Governmental Affairs Committee. Following him would be Susan Collins, R-Maine, who chairs the Appropriations Committee and faces her own tough election in the midterms.
However, another likely option is fellow committee physician Roger Marshall, M.D., R-Kansas, who formed a MAHA Caucus in late 2024. The OB/GYN has publicly been much more aligned with Kennedy’s skepticism of the childhood vaccine schedule and, per Politico, has spent the past few months angling for the chair.