Video (02:46) : The Vermont senator told a crowd in his home state that he is confident that he will win the Democratic nomination.

LOS ANGELES — New York billionaire Mike Bloomberg suspended his presidential campaign and Massachusetts Sen. Elizabeth Warren was reassessing her candidacy Wednesday as the winnowing process in the Democrats’ 2020 nomination fight lurched forward after a consequential Super Tuesday.

Bloomberg became the third failed Democratic presidential contender to exit the race in three days. Like the others, he endorsed Joe Biden, the big winner on Super Tuesday with victories in 10 of 14 states, and called him the best chance to defeat President Donald Trump in November.

Sen. Bernie Sanders lashed back in a Wednesday news conference in Vermont, declaring himself in a “neck-and-neck” race with Biden, despite the former vice president's overwhelming support from the Democratic establishment.

“What this campaign I think is increasingly about is, Which side are you on?” Sanders said. “There has never been a campaign in recent history which has taken on the entire political establishment. That is an establishment that is working frantically to try to defeat us.”

The new sense of urgency from Sanders and his allies came just hours after a resurgent Biden scored victories from Texas to Massachusetts, revitalizing a presidential bid that was teetering on the edge of disaster just days earlier.

Sanders seized the biggest prize with a win in California but won just three other states.

Video (01:32): Democratic voters divided over electability Video (01:32): Democratic voters divided over electability

Warren, Sanders' progressive ally, was huddling with advisers on Wednesday to determine if there was a reason to stay in the race after her Super Tuesday wipe-out. She didn't win a single state and finished in third place, after Biden and Sanders, in her own home state of Massachusetts.

Sanders confirmed that he spoke with Warren early Wednesday

“What Sen. Warren told me is she is assessing her campaign,” he said. “She will make her own decision in her own time.”

While Warren's future is unclear, Tuesday's round of voting helped clarify that the Democratic Party’s presidential field, which featured more than a half-dozen candidates a week ago, had turned into a two-man contest.

Both men are expected to begin receiving Secret Service protection, according to Biden campaign chairman, Rep. Cedric Richmond, who said Wednesday that the House Homeland Security Committee has asked the Secret Service to provide protection to all remaining major presidential candidates.

Biden and Sanders already have Secret Service code names: Biden's is "Celtic" and Bernie's is “Intrepid”

Biden's campaign is embracing his renewed status as a Democratic front-runner and is going on the offensive against Sanders. Richmond blasted the Vermont senator for suggesting that the Democratic establishment is colluding against the progressive's White House bid. Richmond said Biden is earning his votes.

"I just did not know that African Americans in the South were considered part of the establishment," Richmond said, noting that Biden's overwhelming support among black voters gave him wide delegate gains in Alabama, North Carolina and Virginia, among other states.

African American voters, he continued, understand the importance of “nominating a person that they know, nominating a person that can win.”

The Sanders campaign announced Wednesday that it would begin airing three new campaign ads in Arizona, Florida, Idaho, Illinois, Michigan, Mississippi, Missouri, Ohio and Washington, states that hold primaries March 10 and March 17.

One of the new ads features archived footage of former President Barack Obama praising Sanders. It's a not-so-subtle attempt by the Vermont senator to undercut Biden's frequently spotlighting his closeness to Obama.

Trump took to Twitter on Wednesday to call Biden's strong Super Tuesday showing “a perfect storm” and amplify his long-running argument that the Democratic Party would move to stop Sanders from winning the nomination.

“The Democrat establishment came together and crushed Bernie Sanders, AGAIN!” Trump tweeted.

Trump also called Warren “selfish” for staying in the race because it “hurts Bernie badly.”

Biden's victories were powered by Democratic voters who broke his way just days before casting their ballots — a wave of late momentum that scrambled the race in a matter of hours. In some states, the late-deciders made up roughly half of all voters, according to AP VoteCast, surveys of voters in several state primaries. He drew support from a broad coalition of moderates and conservatives, African Americans and voters older than 45.

Sanders' success proved he could deliver in perhaps the greatest test of his decadeslong political career. His success was built on a base of energized liberals, young people and Latinos. But he was unable to sufficiently widen his appeal to older voters and college graduates who make up a sizable share of Democratic voters, according to AP VoteCast.

Gallery: Voters turn out for Super Tuesday primaries Gallery: Voters turn out for Super Tuesday primaries

Biden's strong finish punctuated a dramatic turnaround in the span of just three days when he leveraged a blowout victory in South Carolina to score sweeping victories on Tuesday that transcended geography, class and race. And lest there be any doubt, he cemented his status as the standard-bearer for the Democrats’ establishment wing.

The former vice president showed strength in the Northeast with victories in Massachusetts and Maine. He won delegate-rich Texas in the Southwest, Minnesota in the upper Midwest and finished on top across the South in Virginia, Alabama, North Carolina, Tennessee and Arkansas — in addition to Oklahoma.

Sanders opened the night as the undisputed Democratic front-runner and hoped to claim an insurmountable delegate lead. That didn't happen. And while he scored the night's biggest delegate-prize in California, he won just three other states: his home state of Vermont, Utah and Colorado.

Biden racked up his victories despite being dramatically outspent and out-staffed. Moderate rival Bloomberg, for example, poured more than $12 million into television advertising in Virginia, while Biden spent less than $200,000.

In a statement announcing his departure, Bloomberg vowed to stay engaged in the 2020 election and his ultimate goal to ensure Trump is defeated this fall.

“I’ve always believed that defeating Donald Trump starts with uniting behind the candidate with the best shot to do it. After yesterday’s vote, it is clear that candidate is my friend and a great American, Joe Biden."

Biden aides said they didn't immediately know what to expect out of Bloomberg's endorsement moving forward.

The former New York mayor has committed to turning his massive campaign operation toward the Democrats larger goal of defeating Trump this fall. It was not immediately clear if Bloomberg would use his resources and organization to help Biden in his nominating fight against Sanders.

Democratic presidential candidate Sen. Elizabeth Warren, D-Mass., speaks during a primary election night rally, Tuesday, March 3, 2020, at Eastern Market in Detroit.

Biden's deputy campaign manager Kate Bedingfield said Biden is "thrilled" to have Bloomberg's support. But she said conversations about what Bloomberg's endorsement means in practice are ongoing.

With votes still being counted across the country, The Associated Press has allocated 566 delegates to Biden, 501 to Sanders and 61 to Warren. The numbers are expected to shift as new states report their numbers and as some candidates hover around the 15% vote threshold they must hit to earn delegates.

The ultimate nominee must claim 1,991 delegates, which is a majority of the 3,979 pledged delegates available this primary season.