Did anyone ever doubt for a second before his ghastly Monday morning tweet that Donald Trump would pardon himself? Of course he would. He will do anything he can get away with. Anyone who doesn’t by now acknowledge that is being intentionally stupid.

His lawyers have conveniently affirmed for us that he’ll do anything he can get away with. They say he could murder someone. They say that by definition he can’t break the law—any law. Rudy Giuliani says Trump shouldn’t testify because he might perjure himself; on the one hand, that’s a normal thing for a defense lawyer to say, but on the other, it’s a total through-the-looking-glass moment, because the presumption behind Giuliani’s statement, a presumption we have all tragically come to accept as a given, is that there’s simply no chance that the president of the United States can sit there for one afternoon and not tell a pack of lies.

We are in a crisis, and it’s a crisis of certainty, because we know that the showdown is inevitable. With another president and another lawyer and another political party, we could hope that some combination of the law and respect for constitutional norms would bring them to heel. But with Trump and Giuliani and this Republican Party, we have every reason to think the showdown is unavoidable.

We know that at some point in the future, perhaps next year, we will need Republicans in Congress to step up and say “enough.” It’s a terrifying thought. We’ve been asking this question for 15 months, but we have to keep asking it: What will it take for the Republicans to say he’s gone too far? Maybe a self-pardon. But who knows? The only little flash of backbone they’ve shown has been in saying (mostly in private) that if Trump fired Jeff Sessions, they wouldn’t appoint a replacement. But is that partly just because Sessions is their old colleague? And anyway, Trump could fire Sessions during a Senate recess and then name a recess appointment.

And ultimately, of course, the question of limits on presidential power will likely be decided by the courts. By “the courts,” I mean two: The D.C. Court of Appeals, the most important federal circuit court in the country, and of course the Supreme Court.

Let’s start with the DC Circuit Court. And this is delicious. Bear with me.

Back in 1974, Watergate special prosecutor Leon Jaworski issued a subpoena ordering Richard Nixon to turn over some papers and tapes relevant to the investigation. Nixon turned over some material, but not all, hoping that would satisfy Jaworski. It did not. Nixon’s lawyer, James St. Clair, went to the DC Circuit, and specifically to Chief Judge John J. Sirica, who became a household name in that year of 1974, to quash the subpoena. Sirica refused.

We can easily imagine something similar happening in the future. In which case the question becomes relevant. Who is the current chief judge of the DC Circuit?

Answer: Merrick Garland.

Watch out, Republicans. You may wish you’d have let him get to the Supreme Court after all.

Then, assuming (one hopes) that the DC Circuit does not buy Giuliani and Jay Sekulow’s arguments, up the case will go to the Supreme Court, as indeed United States v. Nixon did in 1974. The court, as you may know, ruled unanimously 8-0 (William Rehnquist, who had worked in the Nixon administration, recused himself) against the president. The court held that presidential privilege did not supersede the law. Nixon turned over the tapes and resigned.

Would today’s Supreme Court rule similarly? We must start thinking about this now. Most observers seem quite confident that the court would never hold that the president is above the law. Joe Scarborough said on Morning Joe on Monday that “the Supreme Court would never follow the president down this rabbit hole.” Former U.S. Attorney Harry Litman, writing on The New York Times op-ed page Monday, wrote that the Trump legal argument is “almost certain to be sharply rejected should it ever be proffered in court.”

Well... I hope they’re right. I think they’re right. Giuliani and Sekulow are arguing explicitly that the president stands above the law. It’s impossible to imagine five justices of the Supreme Court endorsing that view. If a court majority takes that view, the Constitution is worthless, and we are finished as a republic.

So no, I don’t think that would happen. But here’s the thing. A 6-3 decision against Trump is a plausible scenario, with Clarence Thomas, Samuel Alito, and Neil Gorsuch backing full executive power. But even a 6-3 decision would be an utter disgrace. It would be sickening to discover that three associate justices of the United States Supreme Court endorse the idea that if the president does it, it can’t be illegal, and would set a terrifying precedent: Two more Gorsuches named to the court, and boom, we’re done.

St. Clair, Nixon’s lawyer, once said: “The president wants me to argue that he is as powerful a monarch as Louis XIV, only four years at a time, and is not subject to the processes of any court in the land except the court of impeachment.”

A critical mass of Republicans and a unanimous front of high court justices rejected that view 44 years ago. I wish we could be more confident that they would do the same today.