Robert F. Kennedy Jr., a former presidential candidate and environmental activist, endorsed Donald Trump last year and threw his weight behind a campaign to “Make America Healthy Again.” For the past two decades he has been best known for airing skeptical views on vaccines.

If approved, Kennedy will control a $1.7 trillion agency that oversees food and hospital inspections, hundreds of health clinics, vaccine recommendations and health insurance for roughly half the country.

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