Cassidy’s Vaccine Clash With RFK Jr. Fuels MAHA Revolt — And Trump’s Endorsement Turns Up The Heat

Senator Bill Cassidy’s high-profile questioning of Robert F. Kennedy Jr. over vaccine skepticism during last year’s confirmation hearing — and his broader defenses of mass vaccination — have made him a target of the growing Make America Healthy Again (MAHA) movement in Louisiana. That opposition, combined with former President Donald Trump’s endorsement of Rep. Julia Letlow, has intensified Cassidy’s uphill battle for renomination ahead of the May Republican primary.

Why Cassidy Is Vulnerable

Cassidy’s fraught interaction with Kennedy left a lasting impression on MAHA activists, who view his scrutiny and public criticism as a betrayal. Jeff Hutt, a spokesman for the MAHA-aligned super PAC who worked on Kennedy’s 2024 presidential campaign, said Cassidy is “pretty well despised” within the movement. The conflict compounds earlier political blows for Cassidy, who drew conservative ire after voting to convict former President Trump in the 2021 impeachment trial.

MAHA’s Growing Influence In Louisiana

Since Cassidy’s last easy reelection in 2020, MAHA-aligned ideas have gained traction in state politics. Republican Governor Jeff Landry has embraced parts of Kennedy’s agenda, state legislators have proposed measures such as removing fluoride from tap water and banning certain food dyes and artificial sweeteners in school meals, and the state health department has scaled back mass-vaccination messaging.

Trump’s Endorsement And A Changing Primary

Trump’s endorsement of Julia Letlow — and a separate MAHA-aligned dark-money pledge reported to back her — has consolidated anti-Cassidy energy. The political dynamics are further complicated by Louisiana’s move from an open “jungle” primary to a closed primary this year, forcing Cassidy to appeal to a narrower, more conservative GOP electorate.

Other Challengers And MAHA Claims

Several Republican challengers are trying to capture MAHA support. Letlow has publicly praised Kennedy and accepted high-profile backing. State Senator Blake Miguez has promoted himself as a MAHA leader and backed nutrition-focused school reforms, while State Treasurer John Fleming — also a physician — has criticized Cassidy for resisting some of Kennedy’s proposed vaccine reforms.

Policy Positioning And Public Perception

Cassidy, chair of the Senate Health, Education, Labor and Pensions Committee and a trained hepatologist, has walked a careful line: he has repeatedly rejected claims linking vaccines to autism and called agency promotion of that idea “irresponsible,” angering some conservatives. At the same time, he has been criticized by MAHA advocates for not using his committee’s oversight aggressively enough to rein in Kennedy.

Opponents also point to Cassidy’s past fundraisers with pharmaceutical companies as evidence he is too close to industry. To counter that perception, Cassidy has pushed health-policy proposals aimed at curbing industry power — including replacing expired Obamacare subsidies with individual health savings accounts and measures to rein in pharmacy benefit managers.

Electoral Stakes

Political analysts say two issues will likely dominate the primary: Cassidy’s 2021 impeachment vote and perceptions of his loyalty to Trump, as well as the resentment among MAHA supporters over his handling of Kennedy’s confirmation. Cassidy is also emphasizing his strong pro-life record — an issue that resonates in deeply conservative Louisiana and may attract endorsements from pro-life groups frustrated with both Trump and Kennedy.

As the May primary approaches, Cassidy’s campaign must navigate distrust from MAHA activists, skepticism from conservative voters over his past votes, and the growing momentum of challengers aligned with Kennedy’s health agenda. Whether his incumbency and fundraising can withstand that coalition remains an open question.