Anti-vaccine activist Robert F. Kennedy Jr. is expected to announce Monday that he will drop his Democratic bid for president and run as an independent or third-party candidate, adding a new wrinkle to a 2024 race currently heading toward a rematch between President Joe Biden and former President Donald Trump. Kennedy's campaign has teased the announcement in the days leading up to a Monday afternoon speech in Philadelphia. In a recent video, Kennedy said there is corruption “in the leadership of both political parties” and said he wants to “rewrite the assumptions and change the habits of American politics.”