Joe Biden has formally secured the Democratic Party’s presidentialnomination and will face President Donald Trump at the polls in November.
The former vice president has been his party’s presumptive nominee since rival Bernie Sanders ended his campaign in April.
But he needed to secure a sufficient number of delegates from elections this week in seven states and the District of Columbia, with a surge in mail ballots making his position official late on Friday.
In a statement on Friday night, Mr Biden said: “It was an honour to compete alongside one of the most talented groups of candidates the Democratic party has ever fielded and I am proud to say that we are going into this general election a united party.”
There was little of the traditional fanfare to mark the moment as the nation grapples with the coronavirus pandemic and civil unrest.
Mr Biden said: “This is a difficult time in America’s history, and Donald Trump’s angry, divisive politics is no answer.
“The country is crying out for leadership. Leadership that can unite us. Leadership that can bring us together.”
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Mr Biden spent 36 years in the Senate before becoming Barack Obama’s vice president.
This is 77-year-old Biden’s third bid for the presidency and his success in capturing the Democratic nomination was driven by strong support from black voters.
Since clinching the nomination, Mr Biden has worked to build his appeal among progressives, forming joint task forces with Mr Sanders’ campaign to find common ground on key issues like health care, the economy and the environment.
His embrace of his party’s left flank could help him consolidate a Democratic base that remained deeply divided after the 2016 primary and ultimately hurt Hillary Clinton in her defeat to Mr Trump.
But it could also undermine Mr Biden’s attempts to rebuild the Obama coalition, which is often loosely defined as minorities and young people, as well as educated Americans and some working-class voters.
The former vice president has sought, since announcing his candidacy, to cast the election as “a battle for the soul of the nation”, and promised to restore order and dignity to the White House while rehabilitating the US image on the world stage.
Such an approach, though, necessarily focuses on being more of an alternative to Mr Trump than offering radically new political ideas.
And that further underscores Mr Biden’s difficult task of trying to unite his party’s base while appealing to voters from far beyond it.
Mr Biden pledged: “I am going to spend every day between now and November 3 fighting to earn the votes of Americans all across this great country so that, together, we can win the battle for the soul of this nation, and make sure that as we rebuild our economy, everyone comes along.”