“Imagine if it had worked,” Katyal suggests. “Imagine if our president had leveraged his role as commander in chief to convince a foreign power to open an investigation into his political opponent. Imagine if the president’s rival lost the primary because news broke that he was under investigation. Imagine if that meant the president faced a weaker candidate in November 2020 — and won re-election as a result.”

The foreign country could then blackmail our president by threatening to expose the corruption, gaining leverage over our foreign policy. Meanwhile, the president might abuse presidential power in other ways in the belief that impunity was complete. If all this eventually became public, and truth does have a way of trickling out, this would have devastating consequences for the legitimacy of American elections.

This thought experiment perhaps isn’t so far-fetched. We know now that Trump’s pressure on Ukraine caused alarm in the White House and the intelligence community, with National Security Adviser John Bolton likening it to a “drug deal.” Yet for all that uproar, it almost didn’t become public. It was only because of a whistle-blower that the information began to emerge, and the military aid to Ukraine was released only after the White House became aware of the whistle-blower and was being pressured by Congress.

In short, Trump’s plan almost succeeded — and in any case, he will get away with it in the sense that he is sure to be acquitted by the Senate. When Republicans suggest that Trump did nothing wrong, what message does that impunity send to Trump and to future presidents?

The third thought experiment is simple: What if Trump weren’t president, but was like almost any other person in America?

What if he were a high school vice principal who ensured that a police detective’s son would be accepted in advanced placement classes — and then added, “I’d like you to do us a favor, though.” The favor would be an investigation of the vice principal’s ex-wife before their upcoming child custody hearing, in hopes of tilting the outcome in his favor.

In that situation, the vice principal would be fired. We all recognize that no school official or other person in a government bureaucracy should use public power for private benefit.