Robert F. Kennedy Jr., the nephew of former President John F. Kennedy and a prominent anti-vaccine activist, announced on Wednesday that he will run for president as a Democrat in 2024.

The news of Kennedy Jr.’s run for president was expected after filing paperwork to run for president earlier this month. He is the second Democrat to run for president in 2024; progressive Marianne Williamson formally launched her bid last month.

President Biden is widely expected to run for a second term, though the timeline of a formal announcement remains unclear. He told NBC’s “Today” co-host Al Roker in an interview earlier this month “I plan on running, Al, but we’re not prepared to announce it yet.”

Kennedy’s announcement was made at a campaign launch event in Boston on Wednesday. 

Kennedy, 69, the son of former U.S. Attorney General Robert F. Kennedy, has championed environmental causes. But his history of propagating anti-vaccine theories has made him well known, including his founding of a nonprofit that pushed such ideas.

In his announcement speech, Kennedy railed against the “corrupt merger of state and corporate power,” taking aim again at drugs and vaccines.

“It is threatening now to impose a new kind of corporate feudalism on our country,” Kennedy said. “To commoditize our children … to poison our children and our people with chemicals and pharmaceutical drugs.”

While Kennedy’s campaign is seen as a long-shot bid, polling consistently shows that most Democratic voters want someone other than Biden to be the party’s candidate in 2024 and would be open to an alternative. However, the party has signaled it will stand behind the incumbent president if he seeks reelection, saying it would not hold presidential debates between Biden and any challengers that may surface.

It is unclear whether any major Democratic figures will step up to challenge the president for the nomination in 2024.

Updated: 12:51 p.m.