President Joe Biden announced on Sunday that he would not seek re-election, a decision that upends the 2024 presidential contest. The move marks a stunning reversal for the 81-year-old leader, who had steadfastly insisted on continuing his campaign despite mounting doubts about his age and vigor. He has now endorsed Vice President Kamala Harris as the Democratic nominee. [time-brightcove not-tgx=”true”] In a letter posted on social media, Biden acknowledged the growing concerns within his party and the nation about his ability to effectively challenge former President Donald Trump in a rematch.