The hearings were packed to capacity with protesters and fans, while the spillover crowd hung out in hallways and overflow rooms.

The health committee chairman, Sen. Bill Cassidy, R-La., also has expressed concerns about Kennedy's anti-vaccine work. A physician, Cassidy said earlier this month he “had a frank conversation” and “spoke about vaccines at length” with Kennedy. On Tuesday, Cassidy told reporters that he is still unsure if he is backing Trump’s nominee.

President Donald Trump has nominated Kennedy to be the secretary of the U.S. Department of Health and Human Services, which oversees the U.S. Food and Drug Administration, Medicare and Medicaid and helps enforce the Affordable Care Act commercial health insurance rules.

Caroline Kennedy, daughter of former President John F. Kennedy, warned senators of her “predator” cousin ahead of his first confirmation hearing on Wednesday. In a letter first reported by The Washington Post, she wrote that his victims included family members and parents of sick children.

Caroline Kennedy labeled her cousin Robert F. Kennedy Jr. a "predator". Here's what other Kennedy family members have said about RFK Jr.

Robert F. Kennedy Jr. has said vaccines are not safe. His support for abortion access has made conservatives uncomfortable. And farmers across the Midwest are nervous over his talk of banning corn syrup and pesticides from America’s food supply.

In a letter to senators, Caroline Kennedy etches a damning sketch of her cousin, the latest condemnation Robert F. Kennedy Jr. has received from members of his family.

To watch Kennedy's confirmation hearing, viewers can look to the Senate Finance Committee website on Wednesday and the Senate Health, Education, Labor and Pension Committee website on Thursday. C-SPAN and a plethora of broadcast and cable media outlets will broadcast live what is likely to be a contentious confirmation hearing on television.

President Donald Trump has doubled down on his baseless claim that diversity hiring could be to blame for a mid-air plane crash that killed 67 people.Trump ordered a review of all federal aviation hiring and safety decisions after Wednesday night's crash between an American Airlines jet and a military helicopter,

Explore the tumultuous Senate hearings for Trump's Cabinet nominees, including Robert F. Kennedy Jr., Tulsi Gabbard, and Kash Patel

Plus: President Donald Trump orders preparations on a facility at the U.S. naval base at Guantanamo Bay to house up to 30,000 migrants.