Kamala Harris must still win over some key hold-outs if she is to wrap up the nomination (File)
US Vice President Kamala Harris raced Monday to lock in Democratic support and secure the party's nomination to take on Donald Trump in November after President Joe Biden's sensational exit.
Armed with Biden's endorsement, the 59-year-old has quickly won the backing of a flood of Democrats as she prepares to kick off her first full day of campaigning with an event at the White House.
Kamala Harris must still win over some key hold-outs if she is to wrap up the nomination, which could happen as quickly as August 1, while some Democrats are still calling for the party to show transparency with an open primary.
America's first female, Black and South Asian vice president also has a unique opportunity to unify the party, after 81-year-old Biden's historic decision to step aside from the nomination plunged the race into uncharted waters.
The stunning development has brought a jolt of energy to a demoralized party, transformed an election that threatened to turn into a long slog between two unpopular old men, and could give America its first female president.
Kamala Harris spent more than 10 hours Sunday placing calls to over 100 party leaders, members of Congress, governors and other figures, a person familiar with her schedule said.
"On each of those calls, the vice president made clear that she was extremely grateful for the president's endorsement, but plans to work hard to earn the Democratic nomination in her own right," the person said.
She reportedly spoke to former president Barack Obama, one of those who notably held back from endorsing her on Sunday.
'Threat to democracy'
The party has promised a "transparent and orderly process" to replace Biden, who bowed Sunday to Democratic concerns over his age and mental acuity following a disastrous debate performance against Trump.
One possible rival, the independent senator Joe Manchin who has long been a thorn in Biden's side, on Monday ruled out registering as a Democrat and standing against her.
Her campaign said it had raised a stunning $49.6 million in grassroots donations in less than 24 hours since Biden endorsed her on Sunday.
Biden's withdrawal has also upended 78-year-old Trump's election campaign, which was in large part built around attacking Biden as too old.
Kamala Harris' entry not only flips the age issue but puts Trump -- a convicted felon who has faced a series of legal cases over sexual assault -- up against a woman and former prosecutor.
Trump launched a series of invective-filled social media posts after Biden quit, mocking his age and saying he and Kamala Harris posed a "threat to democracy."
The challenges facing Kamala Harris remain daunting in a lightening-fast process
And the vice president has long suffered from poor approval ratings after a lackluster first two years in the White House and she is polling largely neck-and-neck with Trump in the few polls that have looked at a direct match up. That, however, could change as she campaigns, taking charge of her own image for the first time.
Potential convention delegates were being told to expect a vote on August 1 to put Kamala Harris's name formally atop the ticket, more than two weeks before the gathering, CBS reported.
Calls for a contested convention in Chicago starting on August 19 have been muted so far, with potential challengers such as popular California governor Gavin Newsom backing Kamala Harris. Popular Kentucky Governor Andy Beshear also publicly backed Kamala Harris on Monday, adding to speculation that he might be picked for the new vice presidential spot.
'Greatest honor'
Democratic lawmakers and party elders, including at least a third of US senators, some key governors, and Bill and Hillary Clinton, have already rallied behind Kamala Harris.
But many big names -- including Obama, House Minority Leader Hakeem Jeffries and his influential predecessor Nancy Pelosi to Senate Majority Leader Chuck Schumer -- were initially holding back.
The Democratic ticket has been in disarray since Biden's dismal debate performance in June, with Republicans coalescing around Trump after the attempt on his life at a rally in Pennsylvania eight days ago.
Biden spent more than three weeks resisting calls to step down but then dropped his bombshell as he recovered from Covid at his Delaware beach house.
The veteran Democrat said it had been the "greatest honor of my life" to be president and promised to address the nation later this week, offering his "full support and endorsement" for Kamala Harris.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)