I’m sorry to disappoint the would-be heirs of Carl Bernstein and Bob Woodward, but Trump isn’t Nixon. He most certainly isn’t Hitler, the comparison implied by Snyder’s best-selling booklet “On Tyranny.’’ He’s Trump. And what we have to contend with is not tyranny but trumpery. Trump didn’t fire Comey in a desperate bid to keep the net from closing around him but rather because the president’s men failed to restrain their boss from impulsive self-immolation.