Biden bowed out of the race at 1:46 p.m. Eastern time on Sunday, July 21, sending Harris's advisers scrambling to the vice president's residence, where she wore a Howard University sweatshirt while placing more than 100 calls over the first ten hours. Aides rushed to the campaign office in Wilmington, Del., to flip an entire brand from a dead stop - before passing around late-night beer and whiskey to wind down.

By the time the state party chairs released a statement backing Harris at 9:12 p.m. that night, most of her potential rivals for the nomination had fallen in line. State delegations were endorsing. Hundreds of thousands of Americans would gather spontaneously by Zoom to pledge their support over the days that followed.

Brazile thought it would take 48 hours to finish the switch. The Associated Press declared a new presumptive nominee about 32 hours later.

This story about how Democrats handed Harris the nomination, saved themselves from oblivion and restarted the 2024 presidential contest is based on interviews with more than a dozen officials who made it happen, many of whom spoke on the condition of anonymity to describe private events. They told a wide-eyed tale of hope emerging from despair, unity stumbling out of division.

Numbers like this have never been seen.

In less than a week, the coordinated campaign raised more than $200 million, with 66 percent coming from new donors. An affiliated super PAC claimed $150 million of commitments in the first 24 hours. The campaign had more than 170,000 volunteers signed up.