Trump’s potential criminality in this case, which raises questions about his legitimacy as president, creates a dilemma for Democrats. Assuming prosecutors are right about Trump’s conduct, it certainly seems impeachable; a situation in which a candidate cheats his way into the presidency is one the founders foresaw when they were designing the impeachment process. As George Mason argued at the Constitutional Convention, “Shall the man who has practiced corruption, and by that means procured his appointment in the first instance, be suffered to escape punishment by repeating his guilt?”

But in our current moment, removing the president through impeachment is essentially impossible, given that at least 20 Senate Republicans would have to join Democrats. Representative Jerrold Nadler, the New York Democrat who will soon lead the House Judiciary Committee, told me he wouldn’t consider impeachment proceedings without at least some Republican support. There is certainly no appetite among congressional Democrats to pursue impeachment over a campaign finance case, particularly while the special counsel investigation into Russian collusion chugs on.

This leaves us in a dangerous situation. Under Justice Department guidelines, sitting presidents can’t be indicted. Ex-presidents, however, can. Experts on both the left and the right believe that if Trump is voted out of office in 2020, before the five-year statute of limitations on campaign finance violations runs out, he could find himself in serious legal jeopardy.

The conservative Andrew McCarthy, a former prosecutor in the Southern District of New York and frequent Trump defender, wrote on Fox News’s website on Sunday, “The president is very likely to be indicted on a charge of violating federal campaign finance laws.” Representative Eric Swalwell, a California Democrat and former prosecutor, told me, “This president has potential prison exposure.”

The 2020 presidential election was always going to be extraordinarily ugly, but one can only imagine what Trump will do if the alternative to the White House is the big house. “It’s dangerous,” said Swalwell, who worries that Trump could become even more erratic, making decisions to save himself that involve “our troops or internal domestic security.”