Trump Administration Live Updates: Gabbard and Kennedy Nominations Advance in Narrow Senate Votes

Shortly before the vote, Mr. Trump weighed in with a post on social media about rising rates of autism. Both Mr. Trump and Mr. Kennedy have embraced the theory, long debunked, that vaccines are linked to autism in children; Mr. Kennedy’s refusal to disavow such statements were a flashpoint during his confirmation hearings. Numerous studies have found no association.

“20 years ago, Autism in children was 1 in 10,000,” Mr. Trump wrote. “NOW IT’S 1 in 34. WOW! Something’s really wrong. We need BOBBY!!!”

In the end, after a weekend of “intense conversations” with Mr. Kennedy, the White House and Vice President JD Vance, Mr. Cassidy said he had concluded that Mr. Kennedy, as a longtime critic of the nation’s public health and biomedical institutions, was uniquely positioned to restore trust in agencies like the Food and Drug Administration, the National Institutes of Health, and the Centers for Disease Control and Prevention.

“He will be a secretary, but I believe he will also be a partner,” Mr. Cassidy said.

Tuesday’s vote was a demonstration of Mr. Trump’s tight grip on the Republican Party and its allies. Mr. Kennedy’s flip-flops on abortion have worried many in the anti-abortion movement, including former Vice President Mike Pence, who has worked actively against Mr. Kennedy. But anti-abortion groups have not opposed Mr. Kennedy.

One Republican, Senator Thom Tillis of North Carolina, justified his vote in favor of Mr. Kennedy by citing the silence of the anti-abortion movement, as well as the agriculture industry, which is leery of Mr. Kennedy’s vow to ban corn syrup, and the National Rifle Association, which worries about his advocacy for gun safety laws.

“I believe that silence is consent,” Mr. Tillis said.

Mr. Cassidy, the chairman of the Senate Committee on Health, Education, Labor and Pensions, said he had also extracted a series of commitments from Mr. Kennedy to work closely with the panel and to give Congress advance notice of any changes he might make in vaccine policy.

“I want Mr. Kennedy to succeed making America healthy again,” Mr. Cassidy said. “His success will be tied to the health of our nation.”

The vote ended days of political theater, in which the senator from Louisiana seemed so conflicted that many thought he might vote for Mr. Kennedy in committee and then change his vote when the nomination went before the full Senate. Mr. Cassidy made clear on Tuesday that this would not be the case. He said he looked forward to working with Mr. Kennedy if he was confirmed.

A floor vote has not yet been scheduled, but is likely next week. After the committee vote on Tuesday, Senator Ron Wyden, Democrat of Oregon, insisted that Democrats, who have cast Mr. Kennedy as dangerous to Americans’ health, would not give up. He said they would take their case to the American people, presumably with email and phone blitzes and advertising by allied groups.

“We’re going to pull out all the stops,” said Mr. Wyden, the top Democrat on the panel. “There are senators who I believe are going to vote no on the floor.”

He added, “This is not over yet.”

But allies of Mr. Kennedy will undoubtedly have their own campaign. Del Bigtree, a Kennedy ally whose super PAC backed Mr. Trump in the presidential election, said his group would continue to “share the voice of the people” and was likely to run advertisements in support of Mr. Kennedy.

It is still possible that Mr. Kennedy’s nomination could be defeated. He has drawn criticism from two other notable Republicans: Senator Mitch McConnell, a polio survivor and the former Republican leader, and Senator Lisa Murkowski of Alaska, who last week spoke of the importance of vaccination to the survival of Alaska’s Native communities.

If Mr. Kennedy is confirmed, he will oversee a vast, sprawling agency, the Department of Health and Human Services, with 80,000 employees and 13 operating divisions.

In addition to overseeing the nation’s biomedical and public health establishment, the department also has responsibility for Medicare, the government insurance program for older Americans, and Medicaid, the federal-state partnership that provides health coverage to low-income and working people.

Mr. Kennedy’s scant knowledge of those programs gave Democrats pause. During last week’s confirmation hearings, he repeatedly confused the two. Democrats are also alarmed by Mr. Kennedy’s work helping law firms sue vaccine manufacturers who are regulated by the FDA, an agency he would oversee.

Mr. Kennedy’s promise to turn his stake in a vaccine lawsuit over to his son drew a sharp rebuke from Senator Elizabeth Warren, Democrat of Massachusetts, who said, “That’s a fig leaf that is so small it would take a magnifying glass to see.”

Democrats’ opposition to Mr. Kennedy also underscored the shifting alliances in Washington and American politics more broadly. Mr. Kennedy, a scion of a Democratic political dynasty, has angered many in his family, and their party, with his embrace of Mr. Trump. Voting against him made for an uncomfortable moment for some Democrats on the committee.

Among them was Senator Maria Cantwell, Democrat of Washington, whose father, Paul Cantwell, a congressman from Indiana, was with Mr. Kennedy’s father on the night in 1968 when the elder Kennedy delivered the news to the nation that Martin Luther King Jr. had been assassinated.

“I told him in my office, ‘The Kennedys stood up,’” Ms. Cantwell said.

For Mr. Cassidy, the Louisiana Republican, voting against Mr. Kennedy — and defying Mr. Trump — would have been politically perilous. He is up for re-election in 2026 and is already facing a primary challenge from the right.

During last week’s confirmation hearing before the health committee, Mr. Cassidy said he was worried that Mr. Kennedy would use his platform as a cabinet secretary to continue to cast doubt on vaccines and that he was too old to change.

“Does a 70-year-old man, 71-year-old man who spent decades criticizing vaccines, and who’s financially invested in finding fault with vaccines — can he change his attitudes and approach now that he’ll have the most important position influencing vaccine policy in the United States?” Mr. Cassidy asked.

On Tuesday, Mr. Cassidy did not sound entirely convinced that Mr. Kennedy could change. He delivered a pointed reminder on one crucial point — whether vaccines cause autism — where he and Mr. Kennedy continue to disagree.

“Mr. Kennedy has been insistent that he just wants good science and to ensure safety,” Mr. Cassidy said. “But on this topic, the science is good, the science is critical. Vaccines save lives. They are safe. They do not cause autism. There are multiple studies that show this. They are a crucial part of our nation’s public health response.”

Robert Jimison and Christina Jewett contributed reporting.