Joe Biden desperately needed a big win. Frankly the former vice-president needed any win at all, having won precisely zero states in three presidential campaigns. So he hugged South Carolina like a life raft for his drowning campaign.

“To all those of you who have been knocked down, counted out, this is your campaign,” he declared. “Now thanks to all of you – the heart of the Democratic party – we’ve won big because of you. And we are very much alive.”

This is a less-than-subtle slap at pundits and columnists like this one, who previously described Biden’s campaign – just last week, in fact – as having all the vital signs of the living dead.

Joe Biden delivers victory speech

But one sign of life doesn’t stop the calamity heading Biden’s way in just three days, when one third of the delegates will be decided on Super Tuesday.

For Biden to turn this contest around, his big win in South Carolina needs to dominate the news cycle across all the huge media markets in California day after day after day. In a largely non-political state, at a time of widespread concerns about the corona virus, that won’t be easy for any campaign.

But even that won’t be enough. He also needs to convince other moderates to drop out in the next couple of days. They need to tell the voters they’re out before they cast their ballots – because the ballots themselves are already printed.

The omens aren’t good for either scenario. If the Biden campaign is hoping for some giant new momentum in this election, they should just look at the experience of Bernie Sanders’ campaign four years ago.

Sanders won 23 states in 2016 but he didn’t take one of the big states like California, New York or Texas. He lost the delegate count by more than 300, which was not a trivial number, despite his many complaints about the party and the process.

He wasn’t the only candidate who won several states but still lost comprehensively. On the Republican side, you might think that Donald Trump swept the entire race, not least because Trump keeps saying that he did. But Ted Cruz, the strangely sociopathic Texas senator, won 11 states before promptly fading into irrelevance and Trumpian sycophancy.

So what will it take for Biden to turn around this contest?

First, the Biden team discovered on Saturday how to talk about its own reason for being. There is now a frame for the remainder of the primaries that anyone can understand.

“If the Democrats want a nominee who’s a Democrat, a lifelong Democrat, a proud Democrat, an Obama-Biden Democrat, join us,” Biden told his supports in Columbia, South Carolina. “We have the option of winning big or losing big. That’s the choice.”

However, while Biden makes his case for winning big, his rival will actually be winning big.

After Super Tuesday, a large delegate lead for Bernie Sanders – of more than 100, for instance – will be hard to overcome through the primaries. That kind of lead will be even harder to overcome through the convention, where the party’s superdelegates can tip the nomination if no candidate wins an absolute majority in the first ballot.

So the shape of this race comes down to California, where the most recent polls on Friday gave Sanders a lead of between 16 and 21 points over his closest rival there, Elizabeth Warren. For Biden to overcome that kind of advantage would be, as Biden himself likes to say, a BFD.

The Biden campaign might be tempted to keep a split field for some time, with Amy Klobuchar beating Sanders in Minnesota and Elizabeth Warren tying up Sanders in Massachusetts. But a split race means Biden is still lagging Sanders by a wide margin.

It’s not impossible for Biden to even out what is likely to be a Sanders blowout in California and a reasonable Sanders win in Texas. He could sweep the rest of the south – Virginia, North Carolina, Arkansas, Tennessee – to balance out Bernie’s big win out west.

But that scenario would point to a deeply divided Democratic party whose schism would separate the left and center all the way through to the convention. It would be exceptionally difficult to create any sense of unity at that point, at the Milwaukee convention in mid-July.

The only person who could bring the party together is sitting in the Oval Office watching cable news. If there is a single, unifying force for Democrats it is their overwhelming, burning desire to dump Donald Trump.

For his part, Sanders showed no sign of backing out of Virginia, where he spoke to his supporters as his big South Carolina defeat became clear. “I am very proud that in this campaign so far we have won the popular vote in Iowa. We have won the New Hampshire primary. We have won the Nevada caucus,” Sanders said in Virginia Beach. “But you cannot win them all. There are a lot of states out there and tonight we did not win in South Carolina. And that won’t be the only defeat.”

As it happens, defeat is exactly what Joe Biden wants to talk about too: defeat at the tiny hands of Trump. “We have to beat Donald Trump and the Republican party, but we can’t become like them,” Biden said on Saturday. “We have to get back up. The country is so ready.”

South Carolina certainly helped Biden to get back up. We’ll know in three days if the rest of the country is ready to do the same.