Less than a week before Super Tuesday, the crowded Democratic primary field suddenly shrank by three, as Tom Steyer, Pete Buttigieg and Amy Klobuchar decided to give up the ghost before suffering what they expected to be miserable defeats just days later.

But their sudden departures raise a problem: with the states having already printed their ballots, many millions of Americans will still have a chance to vote for them.

So what happens if they do?

Where a candidate drops out after a state’s ballots were printed, they will still appear on them; voters will still be able to vote for them, and their votes will still be counted.

This is the case in California, where the ballot will include 20 candidates – not just Sanders, Biden and so on, but also long-gone candidates like Cory Booker and Andrew Yang. The question in that case becomes whether voters are aware the candidate has dropped out, or whether they’re still so devoted to them that they give them a valedictory vote regardless.

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

Things are different for people who’ve already voted for a dropout candidate by absentee ballot. In some states, a growing proportion of primary votes are cast by mail, meaning a great many may already have been sent in by the time Steyer and Buttigieg gave up the ghost.

Voters who’ve already mailed in ballots for the two men will not, in most states, be able to withdraw their vote or reallocate it to a different candidate, though that’s often because of the candidates’ timing.

In Minnesota, for instance, it is possible to change an absentee vote after it’s been cast – but only up to a week before polling day, too late for Buttigieg and Steyer voters to back somebody else.

However, in many states, voters who’ve received their absentee ballots but not mailed them in yet will be able to show up to polling stations and vote in person, even if their unposted ballot is marked for a candidate who’s dropped out.

One other thing to remember: because Buttigieg won pledged delegates in Iowa, New Hampshire and Nevada, votes cast for him earlier in the primary were, technically, not for nothing.

There is a difference between formally “withdrawing” from the race and “suspending” a campaign. If a candidate merely suspends, as Buttigieg has, they can retain some control of their pledged delegates, in theory allowing them to exert influence or act as kingmaker at a contested convention.