It’s been a very good week for former vice president Joe Biden.

Pretty much written off after disastrous showings in the Iowa caucus and the New Hampshire primary, Biden has come roaring back—first with a decisive 30-point victory in Saturday’s South Carolina primary, and now with ten state-wide victories in today’s Super Tuesday balloting.

In all, Biden won Alabama, Arkansas, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, and Virginia, with Vermont senator Sanders taking Vermont, Colorado, and Utah. The delegate count now stands at Biden 566, Sanders 501.

There is no official count yet in California, where Sanders currently has a 9-point lead. However, since Democratic primaries award delegates proportionally by vote count, there is a good chance that his plurality will not benough to surmount Biden's overall lead in the delegate count.

With 14 primaries held today, as well as the Democrats Abroad Global Primary and the American Samoa caucus, a staggering 1,357 delegates were at stake in the single biggest day of the presidential primaries.

In all, 1,991 pledged delegates are needed to win on the first ballot at the Democratic National Convention in July.

While Sanders has been the Democratic Party’s front-runner since the New Hampshire primary on February 11, the dynamic of the race has changed dramatically since last weekend.

With South Bend, Indiana mayor Pete Buttigieg and Minnesota senator Klobuchar suspending their campaigns (and billionaire Mike Bloomberg seeing his support erode after a couple of lackluster debate performances), the Democratic party establishment—as well as the “stop Sanders” movement—appear to have coalesced around Biden. At this point, he now stands as the main centrist alternative to the Vermont senator’s progressive brand of democratic socialism.

Even so, it should be noted that in was black support—and Biden’s ties to the black community—which secured the former vice president’s huge victory in South Carolina, and helped put him over the top in the Deep South today. But are his victories in Massachusetts, Minnesota, and Oklahoma proof that Biden’s campaign is viable in the rust belt and the western states? A crowded primary schedule for the rest of the month should bring the answer to that question into focus by early April.

Massachusetts senator Elizabeth Warren, meanwhile, has vowed to stay in the race, despite diminishing returns over the past few weeks as well as the loss of her own home state. While not winning any races outright she did manage to rack up 11 delegates today, but it may be too little, too late.

No matter how you slice it, one of the big losers today was billionaire Michael Bloomberg, who spent more than US $170 million—the bulk of it in California and Texas—on Super Tuesday advertising (he’s dropped US $560 million on his presidential campaign in total so far). At this point, all he has to show for his expense is one victory, in the American Samoa caucus—9,600km away from the contiguous United States.

This morning, during a Miami press conference, Bloomberg told reporters that he now believes his only path to the nomination is through a contested convention, which would occur if no candidate can muster the requisite 1,991 delegates on the first ballot. Delegates pledged to a specific candidate would then be released on subsequent balloting, allowing them to vote for whoever they’d like.

It could happen, but it’s a long shot. The potential of a floor fight is something pundits like to talk about every election cycle but it’s not something that commonly occurs. In fact, the last contested Democratic National Convention was in 1952.

The next round of primaries comes next Tuesday, March 10^th, when Idaho, Michigan, Mississippi, Missouri, North Dakota, and Washington state head to the polls.