At 1:45 p.m. on Sunday, only President Biden’s senior staff knew that he would not be running for reelection. Only a minute later, so did the rest of the world.

Biden’s decision follows a string of several months of in-party fighting, with Democratic voters and officials largely split on whether Biden’s age renders him incapable of leading the country for another four years. Democrats have increased calls for him to bow out of the election graciously rather than to cost the party a potential victory in the 2024 elections. Biden, 81, holds the record for being the oldest American president, a distinction he’s had since first entering office at the age of 78. The median age of national leaders is 62, putting Biden among the only 5% of leaders who are in their 80s, according to the Pew Research Center.

In addition to his age, Biden’s approval ratings among progressive Democrats have plunged as a result of his handling of the war in Gaza. Biden’s support of Israel, though it frayed in recent months alongside his relations with President Netanyahu, has alienated some young Black and brown voters.

In a televised message released Wednesday night, Biden said that he was stepping down because there is “a time and a place for new voices, fresh voices — yes, younger voices.” He reflected on his time in office, culminating by stating that it was time to pass the torch of leadership – and the future of the Democratic party – to the next generation. “I revere this office,” he said, “but I love my country more.”

That future now rests in the hands of VP Kamala Harris. Harris, positioning herself as the prosecutor to former President Trump’s convicted felon, has received mass endorsement within the party, beginning with President Biden after he announced his decision to withdraw; Nancy Pelosi voiced her support and President Obama followed yesterday. New York Times election prediction polls thus far show Harris narrowing the gap between her and Trump — a relief for Democratic voters after Biden had fallen significantly behind.

The path forward, however, isn’t entirely straightforward for Harris, despite her going unchallenged for the presidential nomination, the deadline for which was today. Delegates will vote on August 1 for Harris to be declared the official nominee. By August 7, Harris must choose a running mate.

The list of potential candidates for Harris’s running mate has narrowed to eight. The Harris campaign has reportedly requested vetting materials from North Carolina Gov. Roy Cooper, Minnesota Gov. Tim Walz, Pennsylvania Gov. Josh Shapiro and Arizona Sen. Mark Kelly. Additionally, the names of U.S. Secretary of Transportation Pete Buttigieg, Kentucky Gov. Andy Beshear and Illinois Gov. J.B. Pritzker have been widely circulated. Gov. Gretchen Whitmer of Michigan, often mentioned as a contender, stated that she intended to keep her position as governor and did not wish to be considered for the VP role.

In the meantime, Harris will be courting donors and supporters to help fund her unexpected bid. Earlier today, Harris arrived at a sold-out fundraising event – her first since Biden withdrew – in the Berkshires, where organizers say the event raised $1.8 million in donations, dramatically greater than the $400,000 organizers had hoped to bring in.

Support may be strong, but the stakes are high. Harris knows it.

“We got a fight ahead of us, and we are the underdogs in this race, OK?” Harris said, speaking to the crowd at the event. “Level set, we’re the underdogs in this race. But this is a people-powered campaign, and we have momentum.”