The Sunrise Movement, a youth-led climate organization, is urging President Biden to step aside from the presidential race due to concerns that he may not defeat Donald Trump, who denies global warming. Actress Ashley Judd and other prominent figures have also called for Biden to leave, citing worries about his ability to counter Trump effectively. Biden's campaign emphasizes his commitment to fighting climate change and his determination to defeat Trump. As calls for Biden to step aside grow, Kamala Harris is seen as a potential replacement candidate should Biden withdraw from the race, with concerns about his performance and age persisting.