Part of the answer is:
For the rest, let’s look at what he is not. He is not honest. He is not rational. Etcetera. He is a partial reflection of us all. His negativities are, also, our own. What you see is what you get. However, his few virtues are shared by us as well.
Who he is is perhaps best defined by the ‘negative space’ of what he is not. This is especially useful because he is so personally toxic that it allows one to not become too directly engaged in the web of his negativities while trying to define him. You can let then let him go, release him — or not. You have a better chance of not being entangled in his story if you don’t focus directly on his negativities and irrationalities. Do not identify what he is, if it’s negative; instead, say what he is not.
Use the ‘not’ model — not rational, instead of irrational; not truthful, instead of dishonest; etcetera. They mean the same, but not quite. One is the reflection of the other. It’s somewhat akin to looking at Medusa in the reflection of a burnished bronze shield. It affords some protection.
By focusing on what he is not, you began to speak more in terms of the positive. By doing the same with his staunch supporters (or with his vehement opposition), again you bring the positive into play. This way, when you speak of them, your use of ‘not negative’ words de-escalates the situation. And these people all do seem to thrive on negativity.
This exercise also takes one away from personally engaging with negativities while still allowing some positive humane allowances.
Note: I apologize for the disjointed organization of my thoughts on the above. As far as Trump goes, he’s not wrong about all that he does; but, his negativity “poisons the well” and fuels increased partisanship. While we’re busy being distracted by nonsense, meaningful change is left lingering and the middle class is left financing the right wing and left wing partisans’ endeavors.