I've spent seven years trying to understand this, asking a zillion questions, listening to all the rhetoric. I understand it now more than I did, but I think I've hit a dead end on the rest. So I've kind of given up for now.
Clearly he fills a huge need for them. And that need must be so profound and so desperate that this has gone far beyond politics for them. It's a lifestyle for them. Consuming. And they fly into a rage and the flip of a switch. The real "TDS". Like you, I just can't make a logical connection here.
Maybe one day I'll have it figured out, or maybe I'll stumble across a study or book that describes it. Probably not soon. But as I always say, this isn't about him. This isn't political, it's sociological. Psychological. And we god damn well have to figure out what it means about this country.