Nothing about the former vice president's electoral history, hitherto lackluster campaign and the dynamics of this presidential race suggested his Super Tuesday rampage.

The former vice president's three White House campaigns were a punchline until Saturday. It took the 78-year-old 33 years to win a single nominating contest. Now he's suddenly turned into a primary machine, reeling off 11 wins in a span of four nights.

Heading into Saturday's South Carolina primary, Biden -- with lame finishes in the first three nominating contests -- was facing a last stand. Now just three days later, he's the candidate with momentum and has become, for now at least, a political giant.

"We have seen, in that 72-hour period, Joe Biden go from being a joke to a juggernaut," said CNN commentator Van Jones.

Biden shattered all expectations by racking up nine primary wins on Tuesday and then Maine, which CNN projected on Wednesday afternoon would go to the former vice president. He transformed the race, possibly halting the march to the nomination for Vermont Sen. Bernie Sanders , who in some pre-voting scenarios could have emerged from the night with an all-but-unassailable lead in critical convention delegates. His strong showing helped convince the last of his prominent centrist challengers, Michael Bloomberg to quit the race on Wednesday and throw his support behind the former vice president.

No presidential candidate of recent times has rescued a failing campaign in such spectacular fashion. In 2008, Biden's late friend, Sen. John McCain, performed his own famed comeback -- but it unfolded over weeks, culminating in his victories in the Republican primaries in New Hampshire and South Carolina.

Former President Bill Clinton defined himself as the "comeback kid" after placing second in the Granite State in 1992, despite a flurry of scandals. Before then, Richard Nixon rebuilt his brand after losing the 1960 presidential race and a California gubernatorial election. But the rebirth that took him to victory in the 1968 election took years of careful choreography.

Biden's took only three days.

It started well for Biden, then got better

In a harbinger of Biden's bumper night, CNN called Virginia as soon as polls closed at 7 p.m. ET. Then he went on a roll through the South, before setting his sights on states the pundits had already penciled in for Sanders, including Massachusetts , Minnesota and then, incredibly, Texas -- a state Sanders' team had confidently predicted would embrace his democratic socialism.

There was simply no reason to think any of this was possible.

Biden had no money, no advertising blitzes, no organization and didn't even make a campaign stop in half the states he won.

His hope on Super Tuesday would have been to keep Sanders close to provide a rationale for a prolonged campaign and a possible bid to wrest away the nomination at the convention in July.

As it turned out, and even though Sanders looks set to come out on top in California, the biggest delegate prize, the former vice president and his liberal rival look sure to be closely matched in the cumulative delegate count coming out of the most important day of the 2020 election so far, with Biden owning momentum.

President Donald Trump suggested on Twitter Wednesday morning that a "perfect storm" of factors -- Sen. Elizabeth Warren perhaps helping split the progressive vote and the President's oft-repeated and unfounded claim that the Democratic establishment is working to undermine Sanders -- helped propel Biden to victory.

There are "many good states remaining for Joe!" Trump observed.

'We are alive!'

So what led up to this political lightning strike?

A combination of fast shifting factors appear to have opened a previously unforeseen path towards Biden's triumph.

First, Biden's thumping win in South Carolina conferred the aura of a winner, and his dominant showing with African American voters transferred into a run through the South.

The forces that took him to that victory were stirred during a CNN town hall when Biden consoled a pastor who lost his wife in the Charleston massacre, in a gesture that showed his humanity and faith. Then, the late-in-the-day embrace by South Carolina political icon Rep. James Clyburn became the rare case of a political endorsement actually delivering.

Tasting victory in the Palmetto State, Biden stopped acting like a confused, past-his-prime senator shuffling towards his umpteenth term and came across as a winner. In his victory speech, the former vice president hit emotional heights that framed him as an empathetic, decent and unifying figure that voters burned by three tumultuous years could see as an antidote to Trump.

In those moments, Biden's campaign finally reflected the man himself. He is someone who endured through multiple personal tragedies and political reversals, always getting up off the canvas in the end.

As he roared in a victory speech in Los Angeles on Tuesday night: "For those that have been knocked down, counted out, left behind, this is your campaign. Just a few days ago the press and the pundits declared the campaign dead!"

"We are very much alive!"

Biden leaves rivals with tough questions

Biden didn't somehow become a political magician. His romp was enabled by a significant under-performance from Sanders, suggesting the Vermont senator could have a ceiling of support, for all his appeal to younger, more liberal voters.

Perhaps Sanders was victim of his own success. After his early wins this cycle, the prospect of a democratic socialist taking the Democratic nomination and going into the fight against Trump suddenly seemed a very real one.

Tuesday's results were a reminder that many Democrats are far more conservative than their brethren in early states Iowa and New Hampshire, the states that defined the race's first exchanges.

There must now be doubts about the core argument of Sanders' campaign -- that he can expand the Democratic base and beat Trump -- especially given Biden's strength among racially diverse voters. The former vice president also demonstrated a capacity to bond with voters in big city suburbs -- in Houston and Dallas, for instance -- that helped Democrats win back the House in 2018.

Biden can also thank Bloomberg, whose $500 million cash splurge failed to bring him victory in any state , and only a consolation prize of a win in the territory of American Samoa.

JUST WATCHED Biden and family startled as protesters rush the stage as he speaks Replay More Videos ... MUST WATCH Biden and family startled as protesters rush the stage as he speaks 00:45

Biden's years of building political relationships, two terms as Barack Obama's vice president and a connection with Democrats did what Bloomberg's wealth could not do: buy success.

The former New York mayor's rationale for a late entry into the nominating chase was that Biden was too wobbly and under-powered to win the Democratic crown and then beat Trump.

But Biden's resurgence and Tuesday's scorecard appears to deprive the business mogul of any route to the nomination. Biden might also want to thank Warren, who eviscerated Bloomberg in a pair of campaign debates and made him damaged goods in the eyes of voters.

The consolidation of the Democratic centrist establishment around Biden also gave him a huge, unexpected boost on the eve of Super Tuesday. Former South Bend, Indiana, Mayor Pete Buttigieg and Minnesota Sen. Amy Klobuchar suddenly quit the race on Monday and endorsed the former Delaware senator.

Klobuchar almost certainly delivered her home state to Biden, in a race where Sanders had been expected to finish above Biden. Their move allowed Biden to emerge as the centrist champion -- in a way that no Republican managed to do in 2016, allowing Trump to unspool a long series of primary wins despite rarely winning a majority of the vote.

Can Sanders bounce back?

Every step of a presidential campaign is following by a lifting of expectations and a higher bar for a candidate's performance.

So Biden is going to start to be judged as a potential nominee after his Super Tuesday performance. The next big challenge for the candidates comes in next week's CNN debate in Arizona. The clash could be the first one-on-one between Sanders and Biden, if Bloomberg and Warren see no path forward following their disappointing performances on Tuesday. Voters will see the defining clash of the primary -- the fault line that is splitting their party between Sanders' call to revolutionize the US economy, health care and further education systems and Biden's more moderate, unifying, conventional approach.

Biden's hopes going forward may now depend on how quickly he can build on his Super Tuesday triumph and scale up his still rudimentary campaign machinery. He will also be under pressure to maintain his more energized, punchy and emotional stump performances through the grueling weeks to come.

Sanders, with his formidable political machine and almost inexhaustible fundraising network of small donors has the steel and the resources to fight to the end.

And Biden isn't the only one with an improbable comeback story. After a heart attack last year, Sanders was written off -- but he bounced back stronger than ever.

This story has been updated to reflect that Bloomberg has dropped out.