Sanders, the senior minority party member on the committee, pressed Kennedy to concede that health care was a human right, as his father, Robert F. Kennedy, and his uncles, John F. Kennedy and Edward Kennedy, had done. Kennedy again did not give a definitive answer.

Robert F. Kennedy Jr. was confronted with a number of his baseless claims and a vexing abortion issue. But Republican senators treaded lightly.

Robert F. Kennedy Jr. faced aggressive questions about his skepticism of vaccines and other issues during the first of two scheduled Senate confirmation hearings.

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.