Trump is the biggest liar in the history of American politics. And no, I don’t know the precise extent to which Millard Fillmore or Benjamin Harrison was prone to prevarication. And yet, I write that sentence with serene confidence, because I know enough about Fillmore and Harrison and the whole lot of them to know that, while many of them were mediocrities and some operated according to a rather elastic ethical scale, none of them was an outright sociopath.

But Donald Trump is. He will say anything to anyone at any time with utterly no thought of consequences or ever being held accountable. When the moment of accountability comes, he just tells another lie. When he was just a sleazy real-estate grifter, this was merely annoying. But now that he’s the president, and he has an army of propagandists behind him insisting that he is American history’s great truth-teller, it’s sick and it’s dangerous.

There is one set of campaign promises that he is fulfilling to beat the band, and that’s his eagerness to shred the Constitution to punish or round up political enemies and people he doesn’t approve of. He’s managing to fulfill that promise for one simple reason: He and his jackboots can execute those moves unilaterally. Trade and diplomacy, in Ukraine or the Middle East, require negotiation with other parties. But throwing innocent people in foreign prisons is just something he can do, at least until the Supreme Court tells him he can’t (we hope).