What we don’t know, at least with certainty, is what’s behind Trump’s animus. It’s one thing if he hatched a high-level conspiracy with the Russians during the election that he’s ham-handedly trying to cover up; it is another if he knows there was no such conspiracy and believes the investigation is, as he repeatedly says, “a witch hunt.”

This is why it makes no sense for Democrats and the press to blow right by collusion — compelling evidence of which has not yet emerged — to obsess with alleged obstruction instead. If there was no collusion, it is doubtful that Trump has the corrupt motive necessary to make an impeachable obstruction-of-justice case against him.

Absent collusion (or some other sinister secret), Trump is guilty of raging against an investigation that, at the end of the day, really is built on sand. In which case, it’d be better if Trump, secure in his ultimate vindication, lowered the temperature around the investigation. But the scorpion is going to sting the frog — especially if the frog is getting round-the-clock cable coverage.