Biden took a quick leap across New York, where he headlined a pair of high dollar fundraisers and promised he would win the nomination despite his slow start at the start of the vote. Democrats vie for Republican President Donald Trump in the Nov. 3 election.
Here are the highlights of Thursday's election campaign:
BIDEN ON THE MONEY TRAIL
Before a weekend visit to Nevada, which is running its nomination contest on February 22, Biden's fundraisers in central Manhattan on Thursday evening raised what a donor said was close to 800 $ 000.
Biden admitted having failed in Iowa and New Hampshire, but pointed out that 98% of voters had not yet weighed - including black voters in more diverse states who have always supported Biden in opinion polls .
"I am convinced that we will win South Carolina. I think we will win or be in a very close race, one or two, in Nevada, "said Biden of the next two states to vote.
Biden's poor performance so far has eroded his early status as campaign leader.
But he said his support base - African-Americans and working-class voters with a high school diploma - made him the prohibitive favorite on March 3, Super Tuesday, when 14 states weighed in.
Biden set out to lead his rival, Senator Bernie Sanders, questioning the viability of his medicare for all proposal, and asking if Democrats at the bottom of the ballot in battlefield states would be happy to have a self-proclaimed democratic socialist at the top of the ticket.
"I am the only one to run who has ever accomplished great things," he said.
GRAPH: Calendar of the democratic nomination contest of each State and its allocated delegates - here
THE NEVADA UNION WILL NOT SUPPORT
Nevada's largest union, Culinary Workers Local 226, said Thursday it would not approve any of the top eight Democrats before its state caucuses, defusing a war of words with Sanders, who finished first in New Brunswick primary Hampshire this week.
60,000-member union, with disproportionate influence in a state heavily reliant on tourism, opposes Sanders' proposed takeover of government to fund health care, fearing loss of hard-won union illness coverage from members .
Critics of the union over Sanders' plan in recent days have raised the possibility that it may support a centrist like Biden.
Las Vegas Weekly approved Biden and a Democratic colleague, Minnesota Senator Amy Klobuchar, both moderate.
Houston Mayor Sylvester Turner, US representative Ted Deutch of Florida and former North Carolina governor Bev Perdue have all approved Bloomberg.
Biden said he plans to debate Bloomberg's racial discrimination case, while Warren criticized the former New York mayor's previous defense of a discriminatory housing practice known as redlining.
Bloomberg, which self-finances its campaign, was criticized for comments in 2008 that linked the collapse of the US housing market to a redlining ban, in which banks refuse to mortgage entire neighborhoods.
"Once you started pushing in that direction, the banks started to make more and more loans where the credit of the person buying the house was not as good as you would like," said Bloomberg in remarks that surfaced in an Associated Press report.
"We have to face the shameful legacy of discrimination, and not lie about it like Mike Bloomberg did," Warren wrote on Twitter.
Biden told ABC "The View" that he would challenge Bloomberg on the matter and on Bloomberg's past support for a police strategy known as "stop and frisk" that trapped a disproportionate number of blacks and of Latinos during the mandate of the Mayor of Bloomberg.
Bloomberg has not yet qualified for the Democratic debate next Wednesday in Nevada. He does not participate in Nevada or South Carolina, which votes on February 29.
The Bloomberg campaign declined to comment on Biden and Warren's statements. Bloomberg apologized for arresting and searching in November a few days before announcing his candidacy.
BLOOMBERG AIMS AT TRUMP
Bloomberg has drawn crowds of hundreds of people to North Carolina, one of the states voting for Super Tuesday, where he will first appear as a declared candidate.
In a Winston-Salem cafe, Bloomberg said he was "not afraid" of Trump.
"I am a New Yorker. I know how to deal with the New York bullies, ”he said.
Trump launched a new series of insults against Bloomberg on Thursday, calling him a "loser" on Twitter.
Bloomberg's personal fortune, estimated at around $ 60 billion, eclipses that of the president.
Several voters in the crowd at Winston-Salem said they wanted a moderate candidate who could beat Trump in November. Some have said they are looking for an alternative to Biden after worrying about his debating performance and poor performance in the first two voting states.
Cassaundra El-Amin, a black voter, said she was concerned about Bloomberg's stop-and-frisk policy but felt her apologies were sincere.
"I just feel like he could beat Trump," she said.
Report by Jason Lange in Washington and Joseph Ax in New York; Additional reports by Colleen Jenkins in Winston-Salem, North Carolina and Sharon Bernstein in Sacramento, California; Editing by Scott Malone, Jonathan Oatis and Peter Cooney