A good ending, aspiring screenwriters have been taught for generations, should be “surprising yet inevitable.” If everyone sees the ending coming from a mile away, there is no suspense. If the ending seems arbitrary, or runs counter to the grain of the story and the character arc of its protagonists, it undermines the suspension of disbelief. Only when the ending is surprising enough to feel fresh, yet inevitable enough to reveal the protagonists’ deepest nature, do the final scenes leave the viewer satisfied.

For the last year, U.S. politics has felt very much like the plot of a madcap TV show inspired by hysterical realists like Zadie Smith and Don DeLillo. “I’m starting to think that this is the last season of America and the writers are just going nuts,” comedian Jake Flores joked on Twitter in more innocent times, when it still looked as though Donald Trump might still be stopped from winning the Republican nomination.

Since then, America’s plot twists have only become crazier. And yet, they have so far stuck to the maxim repeated over and over in writing workshops: Each unexpected twist and turn has revealed that the nation’s political protagonists are even more depraved than we had thought—and each time it felt as though we should have known this all along.

Does that give us any clue for what hysterical horrors might await us next? All the recent storylines, and every piece of character development, is pointing in the same direction: We are headed toward a constitutional crisis. Why else would Donald Trump violate one of the few constitutional norms he has not yet obliterated by asking naval officers to take a partisan position at a ceremonial event? Why else would he keep repeating that he has the power to pardon anyone he wants—including himself—for any reason at all? And why else would he and his associates be launching one trial balloon after another about firing Special Counsel Robert Mueller?

As Jennifer Rubin points out in the Washington Post, it now seems virtually certain that, in one form or another, we are headed for a constitutional showdown. Even if Trump had nothing to fear from Mueller’s investigation, he would probably be unwilling to accept the legitimacy of an independent probe that so clearly showcases the limits of his rightful authority. But there seems to be something more than the quintessentially populist claim that all the state’s rightful authority resides in him alone. It seems increasingly probable that either he or one of his close associates has done something highly illegal—and that the fear of being found out is starting to set in for good.

It doesn’t take any great foresight to predict what Trump might do under these circumstances. Without shame or hesitation, he will use every tool at his disposal to serve his own interests. If that should seem like the best option, he will be all too happy to fire Mueller or to pardon himself.

Will it really get so far? At this point, what’s more surprising is that anyone still doubts it.

Many commentators are still confidently pronouncing that Trump won’t fire Mueller because such a move would (supposedly) be sure to have disastrous consequences for him. But depending on the nature of his misdeeds, Trump may, on the contrary, have perfectly rational reason to think that he is toast if he lets Mueller do his job. If so, it would be completely in character for him to try a high-stakes gamble like firing Mueller rather than wiggle placidly as the net tightens around him. And while there can now be little doubt about Trump’s character, the likely reactions of the other protagonists in our grubby little drama remain far from clear.

Before the election, most experts dismissed the notion Trump could pose a real threat to America’s constitutional order. “The president’s power is constrained by public opinion,” Eric Posner, a professor at the University of Chicago Law School and frequent Slate contributor, told me in an interview at the time. “Once you’re talking about flagrant violations of constitutional norms, I just can’t imagine it would happen.”

If Posner and most other experts were so optimistic, it was in good part because they believed that there were a lot of things that neither Republican voters nor Republican politicians would ever accept. If Trump ever truly overstepped the bounds of his constitutional authority, or colluded with a foreign power, the assumption went, public opinion would rapidly and decisively swing against him. His approval ratings would plummet. Republican senators and congressmen would withdraw their support. If necessary, they would even vote for him to be impeached.

Obviously, this optimistic prediction simply hasn’t materialized. Even after Trump has blatantly violated constitutional norms by firing James Comey, and even after some of his closest associates have been shown to have conspired with the Russian government to find dirt on Hilary Clinton, close to 40 percent of the American electorate believes that Trump is doing a good job—which is low but not historically low. Meanwhile, Republican members of Congress have become expert at expressing mild concern about his most blatant missteps even as they support his political agenda in most ways that actually matter.

It is possible that Republicans are now approaching their breaking point. Perhaps their willingness to put party ahead of country was far greater than anybody had predicted half a year ago—but it’s now nearing some invisible limit. I certainly hope so. But in light of the last months, I see little reason to assume that something that seems like a clear red line as long as we are approaching it will continue to look like a clear red line once we are looking at it through the rearview mirror.

In short, while we now have all too visceral an understanding of the forces that are driving the plot of America, the ending still remains uncertain. In the optimistic scenario, moderate Republicans like Lindsey Graham and Ben Sasse would finally break with Trump. They would begin by honestly acknowledging that we are hurtling toward yet another red line—and make it abundantly clear that they would pull all support for Trump and his agenda if he fires Mueller or pardons the potential subjects of his investigation. If necessary, they would then follow through on this threat, refusing to make excuses for Trump or to distract from the unique threat he poses through false comparisons to Hillary Clinton.

In the pessimistic scenario, moderate Republicans would keep bumbling along the way they have done for the past six months: They might complain about the president in private or even say a few critical words in public. But they would also continue to vote for Trump’s legislative proposals, to hamstring congressional probes into Russia, and allow Mueller to be fired without a mass revolt.

In short, just how bitter things will get now depends, as it has for the past months, on two simple questions: Will an overwhelming majority of Americans finally turn against Trump? And will Republican senators and congressmen finally start to put country above party? The answer to both is far from clear.

If moderate Republicans finally move to indict Trump, it may, in retrospect, come to seem inevitable that they would eventually find the courage of their convictions. But if they continue to give the president cover by expressing moderate hesitation while aiding and abetting his assault on the American Constitution, that too would, with the benefit of hindsight, come to seem inevitable.