Fourth—and this may be most important—he makes people stupid. In this sense, he’s more like a cult leader or a New Age guru than an intellectual.
He allows people to be comfortable with their prejudices and their hatreds, and he undercuts their ability to think in a critical manner. To an extent, this has to do with his use of emotional and moral blackmail.
Since he portrays everyone who disagrees with him as evil, if you do agree with him you must be on the side of good and right. This is essentially a kind of secular puritanism, and it’s very appealing to many people, for obvious reasons, I think. We all want to think well of ourselves, whether we deserve it or not.