U.S. President Joe Biden has thrown the race for the White House wide open by dropping out of the contest and throwing his weight behind his vice president, Kamala Harris, to be the Democratic nominee to take on Donald Trump in November's election.
Biden, the 81-year-old former vice president and senator, has struggled to recover from a faltering debate performance against Trump in June and has been under pressure from fellow Democrats to stand aside.
The Democratic Party now needs to nominate a candidate for the presidency, with less than a month to go before the party's convention and under four months until the election.
U.S. President Joe Biden raises the hand of Vice President Kamala Harris after viewing the Independence Day fireworks display over the National Mall from the balcony of the White House, Washington, D.C., U.S., July 4, 2024. /CFP
What happens next? Here are four key questions.
Will Biden remain president?
Biden will remain president until January 20, 2025, when the winner of the 2024 election, which will be held on November 5 this year, will replace him. Harris will remain vice president, whether she is the Democratic nominee or not.
Biden "looks forward to finishing his term and delivering more historic results for the American people," White House spokesman Andrew Bates said in a statement to CNN.
Hugh Kieve, 10, of Washington, holds a sign outside the White House as he and his family come out to show support for President Joe Biden, Washington, D.C., U.S, July 21, 2024. /CFP
House Speaker Mike Johnson, a Republican, called on Biden to resign "immediately." "If Joe Biden is not fit to run for President, he is not fit to serve as President. He must resign the office immediately," Johnson said in a statement on Sunday afternoon.
However, there's no realistic process for removing Biden and he hasn't indicated his decision to withdraw is connected to his health.
Will Harris be the Democratic nominee?
Harris, the 59-year-old former senator from California, said on Sunday that she is "honored to have the president's endorsement and my intention is to earn and win this nomination."
The Democratic nominee will be officially decided by 3,949 delegates and around 750 superdelegates at the party's convention, scheduled to begin on August 19 in Chicago, though a candidate could also be nominated via a virtual roll.
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Biden won 99 percent of the pledged delegates during the primaries and caucuses in the first half of this year. The delegates do not flow directly to Harris, but his endorsement makes her the clear frontrunner.
And while she isn't guaranteed to be the nominee, several other factors make her the overwhelming favorite.
She's already on the ticket, so the millions of dollars already raised are hers to use. She has a national profile. She is a woman of color, and to reject her would risk alienating two key voting blocs for the Democratic Party. There's little time left for a proper contest, and a contested convention could be divisive.
Will there be a contested convention?
Initial reaction suggests Democrats are likely to fall in line behind Harris as the nominee, with the vice president holding the best cards (see above), time short and the risk of a contested convention turning ugly.
CBS News reported on Sunday that neither California Governor Gavin Newsom nor Michigan Governor Gretchen Whitmer, two of the leading lights in the party, plan to challenge Harris.
It's possible that other figures will try to contest the nomination, however, with former Democrat Joe Manchin, currently an independent senator, suggesting he might rejoin the party and put his name forward.
U.S. Vice President Kamala Harris holds a campaign event in North Carolina, United States on July 18, 2024. /CFP
Some analysts have suggested that a contest would give greater Harris greater legitimacy and energize the party, others worry it could prove divisive. If Manchin or anyone else were to challenge her, the selection process could become a contested convention if the challenger can attract the backing of 300 delegates across multiple states.
Another issue that could prove interesting at the convention is the nominee's choice of running mate, which in theory is also subject to approval by a vote of delegates.
If Harris were selected as the party's nominee, names such as Arizona Senator Mark Kelly, Pennsylvania Governor Josh Shapiro and North Carolina Governor Roy Cooper have been mentioned as possible vice presidential candidates.
Does Biden's withdrawal change the race for the White House?
Speakers at the Republican National Convention, which has just wrapped up, spent a lot of time castigating Biden's age, capacity and record, and contrasting him with Donald Trump.
While the record will remain an issue if Harris is the nominee, Biden's withdrawal will mean that the 78-year-old Trump will be up against a comparatively youthful Democrat.
The dynamics of the race have changed, but it's notable that Harris' approval ratings are currently as bad as Biden's: the 538 average of polls on July 17 put her approval rating at just 38.6 percent.
Polls trend towards suggesting Harris performs slightly better than Biden nationally against Trump, and marginally better in the critical swing states.
Surveys conducted about a hypothetical nominee can't be treated too seriously, but nationally, the latest poll for CBS gives Trump a three-point advantage over Harris, NBC a two-point margin and Fox a one-point margin, while a Marist poll for NPR gives Harris a one-point lead.