The Senate is expected to vote on Thursday on the confirmation of Robert F Kennedy Jr, a prominent lawyer and vocal vaccine critic, as the US health secretary.
Despite several Republicans expressing deep scepticism about his views on vaccines, Mr Kennedy is expected to win confirmation.
Mr Kennedy, 71, whose famous name and family tragedies have put him in the national spotlight since he was a child, has earned a formidable following with his populist — and sometimes extreme — views on food, chemicals and vaccines.
His audience grew during the Covid-19 pandemic, when Mr Kennedy devoted much of his time to a nonprofit which sued vaccine makers and harnessed social media campaigns to erode trust in vaccines as well as the government agencies that promote them.
With the backing of President Donald Trump, Mr Kennedy believes he is “uniquely positioned” to revive trust in those public health agencies, which include the Food and Drug Administration, the Centres for Disease Control and Prevention, and the National Institutes for Health.
Republican senators have largely embraced Mr Kennedy’s vision, reciting his newly hatched slogan to “Make America Healthy Again” in speeches.
Last week, North Carolina Republican senator Thom Tillis said he hopes Mr Kennedy “goes wild” on reigning in health care costs and improving Americans’ health.
But one holdout — Republican senator Bill Cassidy, a Louisiana doctor — required assurances that Mr Kennedy would not make changes to existing vaccine recommendations before agreeing to back him.
Democrats have remained sceptical, unsuccessfully prodding Mr Kennedy during hearings to deny a long-discredited theory that vaccines cause autism.
And some have raised alarms about Mr Kennedy financially benefiting from changing vaccine guidelines or weakening federal lawsuit protections against vaccine makers.
Mr Kennedy made more than 850,000 dollars (£680,170) last year from an arrangement referring clients to a law firm that has sued the makers of Gardasil, a human papillomavirus vaccine that protects against cervical cancer. While serving as health secretary, he has promised to reroute fees collected from the arrangement to his son.
Mr Kennedy is expected to take over the agency amid a massive federal government shakeup, led by billionaire Elon Musk, that has shut off — even if temporarily — billions of taxpayer dollars in public health funding and left thousands of federal workers unsure about their jobs.