Democratic presidential candidate former Vice President Joe Biden talks with supporters at a campaign event at Wofford University February 28, 2020 in Spartanburg, South Carolina.

Joe Biden chalked up a comfortable win the South Carolina Democratic primary in a needed boost for a flagging 2020 presidential campaign.

The former vice president came into South Carolina looking for a clear mandate to revive his push for the White House. Once the overwhelming leader in national polls, he stumbled in early nominating contests with fourth, fifth and second place finishes in Iowa, New Hampshire and Nevada, respectively.

Biden basked in his first primary victory of his three presidential campaigns on Saturday night, telling supporters "you launched our campaign on the path to defeating Donald Trump." As he urged Democrats in the 14 states that hold primaries Tuesday to back him, he took shots at rivals Sen. Bernie Sanders, I-Vt., and former New York Mayor Mike Bloomberg without naming them.

"Just days ago, the press and the pundits declared this candidacy dead. Now, thanks to all of you, the heart of the Democratic party, we just won and we've won big because of you," he said to applause. "We are very much alive!"

Sanders finished second in the Palmetto State. Billionaire activist Tom Steyer was in third place in the early going, but did not meet the 15% threshold for statewide delegates.

Steyer, who piled his own money into South Carolina, dropped out of the race Saturday night as the state's results came in.

By the time nearly 100% of results were in, Biden had a massive lead with about 48% of the vote. Sanders trailed at about 20%, followed by Steyer at about 11%.

Biden will earn at least 36 of the state's 54 pledged delegates, according to NBC. Sanders will win at least 12. The haul will bring Biden to at least 51 national pledged delegates, second to Sanders' 57 by NBC's count.

Speaking to supporters Saturday, Sanders congratulated Biden for his win. He highlighted his early victories in the race, then added, "you cannot win 'em all."

Biden will now try to translate his triumph to success three days from now on Super Tuesday. Sanders, the national delegate leader, appears poised to widen his edge as he leads recent polls of both of Tuesday's biggest prizes, California and Texas. Surveys suggest a narrow lead for Biden in North Carolina, which awards the third most delegates that day.

After drubbings in the overwhelmingly white Iowa and New Hampshire, Biden said his campaign would get a boost when more racially diverse states had a chance to vote. Polls have found overwhelming support for the former vice president among black voters, though that base appeared to weaken after his struggles.

A majority of South Carolina primary voters, or 57%, identified as black, exit polls found. More than six-in-ten black voters supported Biden, while only 16% and 13% backed Sanders and Steyer, respectively.

The former vice president got a boost in the final days before the primary when House Majority Whip James Clyburn, a South Carolina Democrat and the highest ranking African-American in the House, endorsed him. About half of the state's primary voters Saturday, or 49%, considered Clyburn's choice important, according to exit polls.

More than half of those people voted for Biden, the surveys found.

"My buddy Jim Clyburn, you brought me back!" Biden told Clyburn after the congressman introduced him Saturday night.

Voters had a better opinion of the former vice president than any of his rivals. About three-quarters, or 77%, of exit poll respondents said they have a favorable opinion of Biden, while only 19% said they have an unfavorable view.

For Sanders, 51% of voters had a favorable opinion, while 43% had an unfavorable view.

Only about a quarter, or 26%, of respondents said they have a favorable view of Bloomberg, while 67% said they have an unfavorable opinion. The billionaire businessman will not appear on the primary ballot until Super Tuesday, three days from Saturday.

This story is developing. Please check back for updates.

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