On Saturday, during a campaign speech in Durham, New Hampshire, Donald Trump invoked Vladimir Putin (of all people) as proof that he's being persecuted: "Putin says that Biden's—and this is a quote—politically motivated persecution of his political rival is very good for Russia, because it shows the rottenness of the American political system, which cannot pretend to teach others about democracy." Some commentators see this and other Trump assertions about being persecuted as calculated efforts to fuel his base. But what if Trump really thinks he's being persecuted? What if he has a persecution complex? What if he believes his...