At many points during 2020, people have turned their eyes skyward and asked, “What next?” Fate having been tempted, the news comes this morning that President Donald Trump has tested positive for the coronavirus just a month before Election Day, and while voting in many states is already under way. Although there is no indication yet that he has a severe case of COVID-19, the question of how the electoral process handles a candidate’s serious illness or death is now newly relevant.

There is no real possibility of delaying the election. That would require legislation—the House, the Senate, and the president agreeing quickly on new dates—which is politically unlikely, and would be legally awkward when voting has already started. Instead of postponing or redoing the election, the system relies instead on replacing candidates. The rules for doing so are clear, but what will happen under those rules is anything but.

Both parties provide in their rules for replacing a candidate. Even at this late date, if a candidate died or became so sick that withdrawing was necessary, party leaders would confer and select a replacement. The process by which they would do this is not set, and is entirely up to them. The leadership in this case are the 168 members of the Republican National Committee, and the 400-plus members of the Democratic National Committee. (The RNC allows for the possibility of reconvening its national convention, but doing so this late seems unlikely.)

The obvious replacement for a presidential candidate who dies or drops out is the person’s running mate—who, after all, is running for the post of presidential understudy. But neither party would be formally bound to move the vice-presidential nominee up to the top of the ticket. With the stakes as high as they are, no one should be surprised if other candidates were to make a play for the top spot. And if the running mate were to be chosen, the party would need to pick a new vice-presidential nominee—a process that would necessarily be wide open. Drama would surely ensue.