In testimony to the Senate Finance Committee, Mr. Kennedy seemed to confuse the two government programs that cover more than 150 million Americans.

Robert F. Kennedy Jr. struggled Wednesday to answer questions about Medicare and Medicaid or to provide details about how he would work to drive down health care costs.

Robert F. Kennedy Jr’s confirmation hearings began Wednesday before the Senate Finance Committee. He appears before the Health, Education, Labor and Pension committee on Thursday. Anti-vaccine advocates are celebrating Kennedy’s committee appearance as a ‘historic’ event The anti-vaccine nonprofit group Kennedy used to lead,