As the 1972 presidential campaign wore on, George McGovern, the Democratic candidate for president, began hearing some troubling rumors about his chosen running mate, the Missouri Senator Thomas Eagleton. Eagleton, according to the rumors, had been hospitalized for depression and given electroshock treatments, treatments which up until then had been kept secret from the public.
By late July, it was becoming clear: McGovern had to do something to quash the rumors. And so, on August 1, 1972, McGovern did, asking Eagleton to step down as the nominee three months before the election.
A presidential or vice-presidential candidate had never quit a race in modern history before the Eagleton affair, but this year might offer an even grander political spectacle, thanks to Donald Trump. In recent days, Republicans have been expressing increasing nervousness about Donald Trump's candidacy, with many urging him to quit. Trump might also quit on his own volition, having done the math and decided that bowing out now is better than losing by a landslide in November.
Would Trump actually quit though? Who knows! But we've never seen a candidate like him, and for someone who seemingly entered the race on a whim it wouldn't be outrageous to see him exit in a similar fashion.
And from the standpoint of Republican Party rules, Trump quitting, while unprecedented, would, in fact be a reasonably easy problem to solve. That's mostly because the party's rules lay out pretty clearly what would happen next.
"The Republican National Committee is hereby authorized and empowered to fill any and all vacancies which may occur by reason of death, declination, or otherwise of the Republican candidate for President of the United States," according to the GOP's own Rules of the Party.
The rules go on to define a simple process of replacement: another vote by members of the RNC that could happen at a second national convention or remotely. Whichever candidate gets a majority of the votes, wins the nomination. (The candidates, in this scenario, could come from anywhere—not just those candidates that ran in the primaries and caucuses, which is why some Republicans see House Speaker Paul Ryan getting the nod.)
A far trickier problem, however, are the actual ballots. And it's that process, separate from the nominating process, that could be a bit messier, and is also where timing becomes important. In the U.S., each individual state controls the election process, from making and printing ballots, to counting votes on Election Day, to certifying election results.
Election law in the U.S. is a 50-state patchwork. From voting machines to filing deadlines, each state has different rules. And it's the deadlines in particular that might concern party officials should Trump quit. That's because the closer it gets to the November election, the harder and harder it will get to keep Trump's name from appearing on state ballots, as state deadlines for certifying nominees' names come and go.
It's already impossible, in fact, to keep Trump off all 50: according to the Daily Beast, Delaware's deadline to certify names for the ballot has already passed, meaning that even if Trump quits today you'll still be able to vote for him in Delaware in three months.
Even so, most of these deadlines aren't until September or October, meaning that, for the next few weeks at least, Republicans could likely still get another name on the ballot in most states by November.
State control of elections provides for other sources of potential mayhem, however, because of the Electoral College. Electors in most states are party officials, loyalists who have pledged to vote for their party's nominee should they win a majority of that state's votes. But should state party officials rebel, the national party would have little recourse in stopping it. State parties could, in theory, nominate a different candidate for president, or make their electors unpledged, meaning that they are obligated to vote for no one.
This has happened only a handful of times in modern political history, most recently in 1964, when George Wallace, a Democrat from Alabama, ran against the incumbent President Lyndon B. Johnson. That year, Democratic party officials in Alabama opted to make their electors unpledged, and Johnson's name simply didn't appear on ballots across the state. Instead, voters chose between Barry Goldwater, the Republican nominee, and the unpledged electors, in effect handing the state to Goldwater, though Johnson won the election handily.
The system is designed to handle sudden jolts, in other words, even if the jolt is often a sign of a broader dysfunction within the country or a particular campaign. The results rarely turn out well.
When Eagleton stepped down in 1972 he was replaced by Sargent Shriver, an in-law of the Kennedys and the father of Maria Shriver. McGovern and Shriver went on to lose in November to the incumbent President Nixon and Vice President Spiro T. Agnew, in what was then the biggest landslide in modern political history.