The main thing to understand is that Trump and Vice President Mike Pence could not simply continue to serve beyond Inauguration Day. The 20th Amendment clearly states that “[t]he terms of the President and Vice President shall end at noon on the 20th day of January.” When the clock strikes 12 that day, Donald Trump and Mike Pence’s terms are over and neither has any more claim to the presidency than, say, Barack Obama or George W. Bush.

If that happens, the door opens to a wide array of scenarios, many of which are well within the complex rules set out in the Constitution for choosing presidents. Many of these rules have never come into play in American history, so the results might surprise Americans: There’s a slim chance Trump could emerge as the president, but we could also see a President Nancy Pelosi, President Elizabeth Warren, President Patrick Leahy, President Mitt Romney, or—who knows?—President Elaine Chao.

The bottom line is that if the 2020 presidential election is canceled and Trump wanted to stay in office past Jan. 20, he’d need to find some other way to get “elected.” Here are a few ways, some more likely than others, for how he might try to make that happen—or how opponents might try to block him.