President Joe Biden has easily won South Carolina’s Democratic primary, clinching a state he pushed to lead off his party’s nominating process after it revived his then-struggling White House bid four years ago.

Mr Biden defeated the other long-shot Democrats on Saturday’s South Carolina’s ballot, including Minnesota representative Dean Phillips and author Marianne Williamson.

His re-election campaign invested heavily in driving up turnout in what it saw as a test drive of its efforts to mobilise black voters, a key Democratic block central to Mr Biden’s chances in a likely November rematch against former president Donald Trump.

“In 2020, it was the voters of South Carolina who proved the pundits wrong, breathed new life into our campaign, and set us on the path to winning the presidency,” Mr Biden said in a statement.

“Now in 2024, the people of South Carolina have spoken again and I have no doubt that you have set us on the path to winning the Presidency again — and making Donald Trump a loser — again.”

The Associated Press declared Mr Biden the winner based on an analysis of initial vote results showing him with a decisive lead in key locations throughout the state. He won all 55 of the state’s Democratic delegates.

The president headed a Democratic National Committee effort to have South Carolina go first in the party’s primary, citing the state’s more racially diverse population compared to the traditional first-in-the-nation states of Iowa and New Hampshire, which are overwhelmingly white.

South Carolina is reliably Republican, but 26% of its residents are black.

In the 2020 general election, black voters made up 11% of the national electorate, and nine in 10 of them supported Mr Biden, according to AP VoteCast, an expansive survey of that election’s voters.

The revamped primary calendar will see Nevada go second, holding its primary on Tuesday. The new order also moves the Democratic primary in Michigan, a large and diverse swing state, to February 27, before the expansive field of states voting on March 5, known as Super Tuesday.

New Hampshire rejected the DNC’s plan and held a lead-off primary last month. Mr Biden did not campaign and his name was not on the ballot, but still won by a sizable margin after supporters mounted a write-in campaign on his behalf.