Washington DC - Robert F. Kennedy Jr. came under withering attack from Democratic senators on Wednesday over his history of promoting vaccine misinformation and his sudden embrace of anti-abortion policies during a high-stakes confirmation hearing to become President Donald Trump's health secretary.

The 71-year-old Kennedy scion and former environmental lawyer is vying to lead a department overseeing more than 80,000 employees and a $1.7 trillion budget, just as scientists warn of the growing threat of bird flu triggering a human pandemic.

Critics argue he is dangerously unqualified, citing his promotion of debunked claims linking childhood vaccines to autism, his suggestion that HIV does not cause AIDS, and accusations that he stoked anti-measles vaccine sentiment in Samoa during a 2019 visit, months before a deadly outbreak.

They also point to what they call a glaring conflict of interest: lucrative consulting fees from law firms suing pharmaceutical companies, as disclosed in his financial filings.

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Kennedy pushed back against the criticism in his opening statement, insisting, "News reports have claimed that I am anti-vaccine and anti-industry – I am neither. I am pro-safety."

But he appeared flustered as Democrats took turns confronting him with past statements that contradicted his claims, while also accusing him of hypocrisy over his sudden reversal on abortion.

"I asked Mr. Kennedy to reconcile his many anti-vaccine statements with his handful of pro-vaccine statements," said Democratic Senator Ron Wyden. "Instead, he gave us a word salad and ducked the issue."

Senators are set to continue questioning Kennedy on Thursday.

Kennedy found steadier footing when promoting his "Make America Healthy Again" (MAHA) agenda – a play on Trump's signature slogan – emphasizing the need to combat the nation's chronic disease crisis through healthier eating and environmental responsibility.

His remarks drew cheers from supporters in attendance, including from a group calling themselves "MAHA Moms."

"Americans are the sickest people on Earth," he declared. "Why are we seeing these explosions in diabetes, rheumatoid arthritis, neurological diseases, depression – all these things that are related to toxins in the environment?"

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Yet he notably tempered some of his positions to court skeptical Republicans.

Although he has long championed greener farming practices, he assured rural-state senators that any policy changes would be made with farmers' input – and pledged support for Trump's anti-abortion agenda, including a review of the safety of the long-approved abortion pill mifepristone.

"I have never seen any major politician flip on that issue quite as quickly as you did when President Trump tapped you to become [health] secretary," Senator Bernie Sanders shot back, pointing out that Kennedy had, until recently, been against government limits on abortion.

"One more time for those in the back: Mifepristone is a safe medication," Democratic Congresswoman Ayanna Pressley added on Threads.

For decades, Kennedy – widely known as RFK Jr. – has made false claims about vaccines, including calling Covid-19 shots "the deadliest ever made."

But his unorthodox health beliefs extend far beyond vaccines. They include questioning the role of germs in infectious disease and staunchly advocating for raw milk consumption, even as bird flu spreads among US cattle and has been detected in unpasteurized milk.