Kamala Harris will be confirmed as the Democratic US presidential nominee in an electronic vote that started Thursday, replacing the fanfare of in-person balloting that usually kicks off the party's national convention.
Less than two weeks after Joe Biden ended his reelection bid, his 59-year-old vice president is in full control of the party, having emerged as the only Democrat in the running to challenge Republican Donald Trump in November.
Just under 4,000 delegates - the grassroots activists and politicians allocated during the primary process - sent in signatures backing Harris to be on the ballot for the five-day electronic vote.
No other Democrats have stepped forward to challenge her elevation to the top of the ticket, making her confirmation as the first Black and South Asian woman ever to secure a major party's nomination a formality.
She won the support of 99 per cent of the delegates who signed petitions, the Democratic National Committee (DNC) said in a statement, while no one else met the qualifying threshold of 300 signatures.
"Our delegates have an important responsibility - and opportunity - in the days ahead to cast their history-making ballots for Vice President Harris, ensuring that she will be on the ballot in every state this November," said DNC chair Jaime Harrison.
"Our party has met this unprecedented moment with a transparent, democratic and orderly process to unite behind a nominee with a proven record who will lead us in the fight ahead."
As well as the "pledged" delegates, there are around 700 so-called "superdelegates" who get to vote because they hold elected office - such as state governors or members of the US Congress - or are party officials.
The roll call launched at 9:00 am (1300 GMT) and delegates have until 6:00 pm on Monday to return their votes via an online platform run by the DNC.
Trump's racial smear
The announcement could come late Monday, as Harris hits the campaign trail for a swing across seven crucial battleground states with her newly minted running mate, who has not yet been announced.
The DNC swapped to a virtual process, mirroring the pandemic-hit 2020 vote, because of Ohio's deadline - Wednesday next week - for major parties to submit the names of their certified candidates for the November election.
The DNC has not revealed if the vote will be live-streamed or if a rolling tally will be available to the public and has not disclosed whether it would make the results public before the end of the voting period if they were available.
The virtual roll call marks the official beginning of the 2024 convention, although in practice the festivities get going when thousands of the party's grassroots activists descend on Chicago on August 19.
There will be ceremonial votes for Harris and her running mate in Illinois, in what is expected to be a raucous celebration of her rise from state politics to the top of the ticket.
Trump's White House bid was thrown into chaos on July 21 when Biden, 81, withdrew his candidacy, backing Harris as the Democratic nominee.
Since then, Harris has seen her favorability ratings jump as she has reeled in Trump, who sparked a firestorm of outrage after he claimed falsely on Wednesday that she had decided to "turn Black" for political gain.
The Republican former president has a long history of behaviour and remarks that his critics have denounced as racist, from calling Mexican immigrants rapists and pandering to white supremacist marchers to dining with notorious anti-Semites.
He was sued for racial discrimination as a young developer, and once said a group of Black and brown American lawmakers were "from countries whose governments are a complete and total catastrophe" and that they should "go back" to those countries.