Updated at 9:15 a.m. Wednesday with Bloomberg dropping out, Warren taking stock

Joe Biden, his campaign left for dead just weeks ago, roared back to the top of the Democratic field with a narrow win in Texas and decisive wins across the Super Tuesday battle map, as Democrats closed ranks in anointing him the centrist counterweight to Sen. Bernie Sanders.

Billionaire Mike Bloomberg was the latest to fall in line, dropping out on Wednesday morning, $500 million poorer, and throwing his support to Biden.

The tussle for the direction of the party generated rare excitement among Democrats, with long lines at polling sites in North Texas and massive delays in Houston, where the last voter still in line when polls closed at 7 p.m. cast a ballot after 1:30 a.m. on Wednesday.

Biden held a 3-point lead over Sanders in Texas when he was declared the winner at 1 a.m., though both stood to scoop up delegates.

Sanders won California, the biggest trophy of the night. But that was fully expected. He led in Texas by a wide margin just a few days before the primary, so Biden’s victory gave rocket fuel to an invaluable comeback-momentum narrative.

With wins in the South, Northeast and Midwest, Biden emerged decisively as the choice of Democrats seeking a unifier to take on a president they despise, swamping progressives enthralled by Sanders’ vow to overhaul the nation’s social contract.

“It’s a good night. It’s a good night and it seems to be getting even better!” Biden declared in Los Angeles, before Texas results were announced, shouting with excitement. “Things are looking awful, awful good.... Just a few days ago, the press and the pundits declared the campaign dead.... And we’re told when we get to Super Tuesday it may be over. Well it may be over for the other guy!"

With the Democratic race evolving at breakneck speed, signs pointed to a two-person race once the dust settled but with Biden, 77, a former vice president, in command, riding high after a landslide win in South Carolina on Saturday.

Sanders, 78, a democratic socialist, won the big prize, California, and he won at home in Vermont, and in Colorado and Utah. But it wasn’t the night he’d hoped for.

“Tonight I tell you with absolute confidence: We are going to win the Democratic nomination, and we are going to defeat the most dangerous president in the history of this country,” he told cheering supporters in Essex Junction, Vt.

Call it a W. Thank you, Texas. pic.twitter.com/iXFI1ys9wi — Joe Biden (Text Join to 30330) (@JoeBiden) March 4, 2020

And it was a truly rough night for the other two major contenders.

Sen. Elizabeth Warren wrestled with the embarrassment of losing at home in Massachusetts. Biden’s win amounted to a major upset over both her and Sanders, who had led Warren in polls just days earlier. She planned to spend Wednesday assessing her options.

The other major candidate, billionaire media mogul Michael Bloomberg, a former New York mayor, spent $500 million from his vast personal fortune, with little to show for it but a stack of invoices from TV networks and Facebook, though he did win American Samoa and at least four delegates there – small consolation on a night when Democrats parceled out 1,344 pledged delegates, a third of the total.

He joins a list of candidates through history who tried to bypass the initial small state contests without success. He did top the 15% threshold in Texas needed to get some statewide delegates.

“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,” he said.

Biden lauded his work on gun violence and climate change, and welcomed his support.

.@MikeBloomberg, I can’t thank you enough for your support—and for your tireless work on everything from gun safety reform to climate change. This race is bigger than candidates and bigger than politics. It’s about defeating Donald Trump, and with your help, we’re gonna do it. — Joe Biden (Text Join to 30330) (@JoeBiden) March 4, 2020

Bloomberg would have risked becoming a spoiler, sapping votes from Biden and aiding Sanders. Warren’s calculus is somewhat different. She has been competing with Sanders for progressive support, and the party establishment may not mind if she remains a bit longer to put a drag on him.

The night unfolded well for Biden. He won the first prizes of the night — Virginia, where Bloomberg had outspent him 50-1, then North Carolina and Alabama, and later in the evening, Tennessee and Arkansas, extending his streak in the South.

He passed Sanders’ delegate tally.

Adding insult, he nabbed Oklahoma, which Sanders had won in 2016, and five states he hadn’t even campaigned in.

Undeniable turnaround

After a February that began with drubbings in Iowa, New Hampshire and Nevada, and punctuated by listless performance on the stump, Biden’s turnaround was undeniable, and he moved fast to show that Democrats were falling in line behind him.

On Monday evening, 48 hours after his comeback in South Carolina, three former contenders converged in Dallas to confer their blessing on Biden. Beto O’Rourke, still popular among Texas Democrats after a near-miss in 2018 against Sen. Ted Cruz, and Minnesota Sen. Amy Klobuchar, joined Biden at a rally at Gilley’s honky tonk. Pete Buttigieg, who ended his presidential campaign Sunday, endorsed him earlier in the evening after a dinner at Chicken Scratch in West Dallas.

The show of force was dramatic, providing a jolt Biden needed to roar past Sanders.

“We need somebody who can fight but we need just as badly, just as badly... a president who can heal the country,” Biden said.

An NBC exit poll showed that voters who waited until Tuesday to make up their minds went 2-1 for Biden over Sanders.

His 30-point win in South Carolina, where black voters dominate the Democratic electorate, showed that he can attract broad support. In Texas, he enjoyed strong support from black and Hispanic leaders.

Biden’s turnaround even drew props from the pundit-in-chief, President Donald Trump.

He complimented Biden on Wednesday for an “incredible comeback,” called Warren a “spoiler” and mocked Bloomberg, his fellow New Yorker, for spending so much and getting so little.

On Tuesday he eagerly stoked the infighting among his opponents.

“There’s no question the establishment — the Democrat establishment — is trying to take it away from Bernie Sanders," he said, but whether Sanders or Biden, “whoever is it I don’t care.”

Sanders coalition shrinking

Sanders had boasted that his “revolution” was inspiring legions of new voters. That would ease fears that he scares off independents and moderate Democrats with vows of free college and health care and higher taxes to pay for them.

But exit polls suggested his boasts were empty. His coalition had shrunk from 2016, when he was runner-up to Hillary Clinton.

He used his Tuesday night speech to press his call for a broad based “movement," and to poke at Biden for supporting wars and trade deals that he opposed.

“I don’t know what will happen but … if we have another candidate who has received contributions from at least 60 billionaires, we’re going to win that election.” As for Bloomberg, Sanders said, “we’re going to tell him in America, you cannot buy elections.”

Former Rep. Beto O'Rourke endorses Democratic presidential primary candidate Joe Biden during a rally at Gilley's on March 2, 2020 in Dallas. (Juan Figueroa / TNS)

War of attrition looms

After Tuesday, only Sanders and Biden had a mathematically realistic shot at clinching the nomination.

But with the race still splintered, it was more likely that no candidate would arrive in Milwaukee in July with the magic number of delegates.

Bloomberg acknowledged that a contested or so-called “brokered” convention is his only path.

"I don't think that I can win any other ways," he said while stumping in Miami, with polls still open in Super Tuesday states.

Sanders favored a contested convention in 2016, when Clinton led in delegates but remained short of a majority.

In recent weeks, with the plurality in his own column, Sanders has argued the opposite way, insisting that it would be unfair to deny the nomination to a candidate who emerges from the primaries with the most delegates.

Two laggards

Bloomberg, the world’s 9th wealthiest individual with a fortune of roughly $60 billion, had bombarded Texas and other states with ads.

You’ve probably been accosted online, too. Bloomberg has spent $60 million on Facebook ads alone in the last two months. About a tenth of that has been aimed at Texans, according to Facebook’s political ad library.

Bloomberg took solace in the strides he’s made.

“Here’s what is clear,” he told supporters in Florida on Tuesday night. No matter how many delegates he would nab, “in just three months we have gone from just 1% to being a contender for the Democratic nomination for president.”

Sanders — the runner-up on Facebook — spent the comparatively small sum of $10.8 million.

As for Warren, her prospects were already fading heading into Super Tuesday. Sanders had nudged past her in Massachusetts in recent polls, which threatened to undermine her pitch that she is the candidate most able to unify the party.

Warren hasn’t won any of the first 18 states. But as polls were closing on the East Coast, her campaign announced appearances in Michigan on Friday, and in Arizona and Idaho on Saturday, a message reinforced hours later in a donor appeal.

Speaking to supporters in Detroit one week before the Michigan primary on Tuesday night, she dismissed the “guess what your neighbors are up to” game from pundits who often get it wrong.

She called herself “the woman who’s going to beat Donald Trump" and asked voters to “cast a vote from your heart, and vote for the person you think will make the best president.”