President Joe Biden dropped out of the 2024 race for the White House on Sunday, ending his bid for reelection after a disastrous debate with Donald Trump that raised doubts about the incumbent’s fitness for office with the election just four months away. It was a late-season campaign thunderstrike unlike any in American history.

The decision comes after escalating pressure from Biden’s Democratic allies to step aside following the June 27 debate, in which the 81-year-old president trailed off, often gave nonsensical answers and failed to call out the former president’s many falsehoods. Biden endorsed Vice President Kamala Harris to take on Trump, and encouraged his party to unite behind her.

Biden plans to serve out the remainder of his term in office, which ends at noon ET on Jan. 20, 2025.

“It has been the greatest honor of my life to serve as your President. And while it has been my intention to seek reelection, I believe it is in the best interest of my party and the country for me to stand down and to focus solely on fulfilling my duties as President for the remainder of my term,” Biden wrote in a letter posted to his X account.

Nearly 30 minutes later, Biden throw his support behind Harris, the party’s instant favorite for the nomination at its August convention in Chicago.