Robert F. Kennedy Jr., the nephew of former President John F. Kennedy and a prominent anti-vaccine activist, announced on Wednesday that he would be running 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 own 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.”