President Joe Biden announced Sunday that he will end his presidential re-election campaign, bringing an abrupt and humbling conclusion to his half-century-long political career and scrambling the race for the White House just months before Election Day.

Biden, 81, could not reverse growing sentiment within his party that he was too frail to serve and destined to lose to Donald Trump in November.

His withdrawal caps a singular national political career, bookended by Richard Nixon’s fall and Trump’s rise. He mounted four presidential bids. He spent 36 years in the US Senate representing tiny Delaware. He rose to the chairmanships of the powerful judiciary and foreign relations committees. And he served eight years as Barack Obama’s vice president.

Biden’s decision to exit the race less than a month before his party’s convention and a few months before voters head to the polls is unprecedented in the modern political era. The last sitting president to abandon a reelection bid was Lyndon Johnson, whose expansion of the Vietnam War in the 1960s split the Democratic Party. But Johnson’s announcement came in March 1968 — eight months before that election.

“We’re in uncharted waters,” said Barbara Perry, a presidential studies professor at the University of Virginia’s Miller Center. “No president has dropped out or died this close to the convention.”

Replacing Biden atop the Democratic ticket is likely to set off internal Democratic tremors as ambitious officials maneuver to become his successor. Factions have already formed around sitting Vice President Kamala Harris and prominent governors, including Michigan’s Gretchen Whitmer and California’s Gavin Newsom.

https://www.nbcnews.com/politics/2024-election/president-joe-biden-drops-2024-presidential-race-rcna159867