Since the end of World War II, there have only been three incumbent presidents, all Democrats, who turned down running for a second term: Harry Truman, Lyndon Johnson, and Joe Biden.
The 46th president faced mounting pressure from his Democrat allies and legacy media outlets to bow out of the race since June 27, when he delivered a botched debate performance against Trump that was riddled with garbled remarks and where the president lost his train of thought and appeared more subdued than during other recent public events.
The debate reignited concern among conservatives and critics that Biden's mental acuity had slipped, while it marked the beginning of a pressure campaign among Democrats to oust Biden in favor of a candidate they believed is better suited to take on Trump.
Dozens of members of Congress began publicly thanking Biden for his work in the White House and decades in public office while calling on him to pass the torch to another candidate. He made the announcement just more than a week after an assassination attempt on Trump's life during a rally in Pennsylvania and just days after the Republican National Convention wrapped up in Milwaukee, where Trump was certified as the Republican Party's nominee.
Shortly after his announcement on Sunday afternoon, Biden endorsed Vice President Harris to pick up the mantle and make a run for the party's nomination. As of Tuesday, Harris had enough delegates to lock up the nomination, which will be certified by the DNC next month.
