President Biden on Sunday abruptly abandoned his campaign for a second term under intense pressure from fellow Democrats and threw his support to Vice President Kamala Harris to lead their party in a dramatic last-minute bid to stop former President Donald J. Trump from returning to the White House.
“It has been the greatest honor of my life to serve as your President,” he said in a letter posted on social media. “And while it has been my intention to seek re-election, 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.”
Mr. Biden then posted a subsequent online message endorsing Ms. Harris. “My very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President,” he wrote. “And it’s been the best decision I’ve made. Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year. Democrats — it’s time to come together and beat Trump. Let’s do this.”
The president’s decision upended the race and set the stage for a raucous and unpredictable campaign unlike any in modern times, leaving Ms. Harris just over 100 days to consolidate support from Democrats, establish herself as a credible national leader and prosecute the case against Mr. Trump.
Although Democratic convention delegates must ratify the choice of Ms. Harris to take over as standard-bearer next month, Mr. Biden’s endorsement meant the nomination was hers to lose and she appeared in a powerful position to claim it. While Mr. Biden, 81, remained president and still planned to finish out his term in January, the transition of the campaign to Ms. Harris, 59, amounted to a momentous generational change of leadership of the Democratic Party.
The president said he would “speak to the nation later this week in more detail about my decision.” One person informed about the matter said Mr. Biden had told his senior staff at 1:45 p.m. that he had changed his mind, an announcement that surprised many aides who had been told as recently as Saturday night that his campaign was still full speed ahead. It was not immediately clear whether he wrote the letter himself or had help, nor did his aides know when or how he might address the nation.