President-elect Donald Trump is expected to nominate former presidential candidate and anti-vaccine activist Robert F. Kennedy Jr. to lead the Department of Health and Human Services, according to a person with direct knowledge of the selection.

The expected pick, which will roil many public health experts, comes after Trump promised to let Kennedy "go wild" with health and food policy in his administration after Kennedy dropped his own presidential bid to endorse the now-president-elect. It's also a sign of the opening Trump sees after he scored a decisive electoral victory and Republicans won a comfortable majority in the Senate.

Trump could still select someone else for the post. The Trump transition couldn't immediately be reached for comment.

"He's going to help make America healthy again. ... He wants to do some things, and we're going to let him get to it," Trump said in his victory speech. "Go have a good time, Bobby."