Comey’s disclosure might also be defended on the grounds of necessity. Suppose that a president orders that something clearly illegal be done, something so heinous that it rises to the level of an impeachable offense. Comey has hinted that that is what Trump had asked him. That would clearly distinguish it from the Petraeus case.

But then it’s more complicated than that. First, Petraeus’s disclosures were to a biographer, a West Point grad, and there was clearly no intention that the information be leaked to anyone else. In Comey’s case, on the other hand, the intention was to get the information into the hands of the New York Times as quickly as possible. Second, what Comey revealed clearly didn’t amount to an impeachable offense. Instead, it looked like payback from a just-fired employee, and Comey’s malice became all too clear when he went out of his way to repeat salacious and false rumors about Trump, for no other conceivable reason than to embarrass a person he hated.

That’s one of the things which bothered me most about Comey’s testimony — his twice-repeated assertion that the contemporaneous notes he took of his conversations with the president were “unclassified.” In other words, he was telling us that he got to decide, on his own authority, what was classified and what was not. However, the information in question concerned whether the president urged that an investigation into General Flynn’s foreign activities and intelligence sources be abandoned, which does look like a classified national security matter under Executive Order 13526. In the circumstances, I would have expected that only the president could declassify the information.