Just under a month ago, as Democrats scrambled to certify results in the Iowa caucuses after an election app went on the fritz, Pete Buttigieg stood before a crowd in the Hawkeye State and thanked those voters for making history.

It would be a while before those results were actually in, but Mr Buttigieg and his campaign were confident that he had won — and he did win — the most delegates in the state, propelling the campaign of a 38-year-old with scant political experience forward as a front-runner in the Democratic nomination for president.

Oh, how quickly things can change: on Sunday, Mr Buttigieg rerouted his plane to his home town of South Bend, Indiana. And, there, just weeks after that triumphant showing just two states to the west, Mr Buttigieg suspended his campaign.

The decision marked the latest scramble in a tumultuous primary season that saw Mr Buttigieg go from winner to loser quite fast, with the man who came in fourth place in Iowa, Joe Biden, rising to the top of the moderate field following a decisive win in South Carolina.

So, what will it mean that a once leading candidate has now suddenly dropped out? Here’s what you need to know.

Democratic candidates compete on the campaign trail: In pictures Show all 18 1 /18 Democratic candidates compete on the campaign trail: In pictures Democratic candidates compete on the campaign trail: In pictures Jessica Canicosa, a precinct captain for Bernie Sanders, waits to greet caucus voters at Liberty High School in Henderson, Nevada REUTERS Democratic candidates compete on the campaign trail: In pictures Hotel workers at the Bellagio in Las Vegas get to grips with voting papers during the Nevada caucuses AFP via Getty Images Democratic candidates compete on the campaign trail: In pictures A caricature of Bernie Sanders is projected on to a tree during a rally in Las Vegas EPA Democratic candidates compete on the campaign trail: In pictures A woman waits to have a photo taken with Elizabeth Warren during a town hall meeting in Las Vegas REUTERS Democratic candidates compete on the campaign trail: In pictures The threat of coronavirus and other germ-borne illnesses was on some voters' minds at the Democratic caucuses in Henderson, Nevada Getty Images Democratic candidates compete on the campaign trail: In pictures Former vice-president Joe Biden takes a selfie with a voter in Las Vegas ahead of the Nevada caucuses REUTERS Democratic candidates compete on the campaign trail: In pictures Amy Klobuchar changes her shoes backstage after giving a speech in Exeter, New Hampshire AFP/Getty Democratic candidates compete on the campaign trail: In pictures A warmly-wrapped-up dog attends an Elizabeth Warren event at Amherst Elementary School in Nashua, New Hampshire AFP/Getty Democratic candidates compete on the campaign trail: In pictures Bernie Sanders, who romped to victory in New Hampshire against Hillary Clinton in 2016, talks to the media in Manchester Getty Democratic candidates compete on the campaign trail: In pictures Joe Biden was hoping to improve on his poor showing in Iowa in the New Hampshire primary Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren, renowned for giving time to supporters for selfies, works the crowd at the University of New Hampshire in Durham Getty Democratic candidates compete on the campaign trail: In pictures Joe Biden takes a selfie with a supporter and his child outside a campaign event in Somersworth, New Hampshire on 5 February Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren and Bernie Sanders quarrel after a confrontation in a TV debate in which Sanders claimed that Warren was not telling the truth about a conversation in which she claimed he had said a woman could not win the presidency on 14 January AP Democratic candidates compete on the campaign trail: In pictures Supporter Pat Provencher listens to Pete Buttigieg in Laconia, New Hampshire on 4 February Getty Democratic candidates compete on the campaign trail: In pictures Pete Buttigieg speaks at a campaign event in Concord, New Hampshire while awaiting the results of the Iowa caucus Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren is presented with a balloon effigy of herself at a campaign event in Nashua, New Hampshire on 5 February Reuters Democratic candidates compete on the campaign trail: In pictures A Trump supporter rides past a rally for Amy Klobuchar in Des Moines, Iowa on 14 January AP Democratic candidates compete on the campaign trail: In pictures A man holds up a sign criticising billionaires in the presidential race in front of Michael Bloomberg in Compton, Califronia. The former New York mayor skipped the first caucus in Iowa and instead campaigned in California on 3 February Reuters

Where he wants his votes to go

In announcing his withdrawal from the race, Mr Buttigieg said that he did not see a viable path towards victory in the Democratic race, but gave some suggestion as to what he would like his supporters to do now that he’s gone. He spoke of “unity” in the effort to defeat Donald Trump. His aides later said he did not want to be a “spoiler”.

But an adviser also told Reuters that he was dropping out in large part because he believed staying in the race could help Bernie Sanders, the current front-runner, to run away with the election. So, conventional wisdom would point to Mr Biden as the likely candidate, after his strong showing in South Carolina — not to mention Michael Bloomberg’s horrible debate performances — that has signalled to many within the moderate arm of the Democratic Party that he’s the guy to coalesce around.

Where they will actually go

This is a big question, especially with just a day (as of this writing) until voters head to the polls in Super Tuesday states (in many cases, early votes may have already been cast). It’s hard to say with certainty, even, if Mr Biden’s decisive victory in South Carolina on Saturday will tip the scales much.

Still, while it’s hard to say with certainty where his supporters might go, the absence of Mr Buttigieg has the very real chance of helping several candidates across the country, and hurting Mr Sanders.

That’s because many of the leading alternatives to Mr Sanders are flirting with the 15 per cent viability mark that is necessary to win delegates in state and congressional contests. (Mr Sanders, meanwhile, has less to worry about on that front and it is highly likely that he passes that threshold in virtually all of the 14 states to vote on Tuesday).

That means that Buttigieg supporters could help Elizabeth Warren, Mr Biden, Mr Bloomberg or even Amy Klobuchar to push past that threshold, and keep Mr Sanders from being the only candidate to receive delegates.

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It’s worth remembering that voting blocs aren’t monoliths, and ideological purities aren’t necessarily the only factor for how voters might rank their candidates. By and large, voters have said beating Donald Trump in November is their biggest concern — so a relative progressive like Ms Warren might attract Buttigieg supporters in much the same way that relative moderates like Mr Biden or Ms Klobuchar might.

There are six contenders in the race now. According to a recent Quinnipiac poll released last month, Ms Klobuchar is the second choice for a good 26 per cent of Buttigieg voters, which makes her tied with Ms Warren, who also was named by 26 per cent of Buttigieg supporters as their second choice.

Behind those two were Mr Biden, at 19 per cent, and then Mr Sanders, at 11 per cent. Mr Bloomberg was the second choice for just 9 per cent of Buttigieg voters.

But, polls vary. A Morning Consult poll released in February, for instance, found Ms Warren to be the second choice for 19 per cent of Buttigieg voters, Mr Biden as second choice for 19 per cent of those voters as well, and Mr Sanders as second choice for 21 per cent of those voters. Another 17 per cent said Mr Bloomberg was their second choice in that poll. Ms Klobuchar was not listed.

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What about the 'money primary'?

One astounding aspect of Mr Buttigieg's campaign was that he attracted the kinds of high dollar donors that have become mainstays of most major presidential campaigns in recent elections (Mr Sanders, and, to a lesser degree, Ms Warren are something of outliers on that front). And, through those massive fundraising totals, Mr Buttigieg was able to remain competitive with $24.7m raised in just the final months of 2019.

So, who might benefit from his departure? Well, at least one influential Democratic donor aligned with Mr Buttigieg, Orin Kramer, has already indicated he's backing Mr Biden, which is a move other donors are reportedly considering, according to the Wall Street Journal.

What's next for Mr Buttigieg

Now that he has dropped out of the race, the 38-year-old former mayor of South Bend has been heralded by columnists as a keen political talent, and one with a bright future in Democratic politics.

In the near term, he will likely be considering who to endorse in the Democratic race, assuming he hasn't decided who to throw his weight behind already. Mr Biden's campaign would certainly be hoping for that kind of recognition.