Bill Maher made a good point on his show this week about ignoring the clown f-cking the horse and keeping your eye on the real action. Maybe it will help to simply drop all of the moral argumentation against Trump (and believe me, one could develop an entire catechism about the ways in which the Republicans in general and Trump is particular violate pretty much every human moral norm) and simply address the purely cold, logical effects. For example, Pruitt is no doubt a monster, but the destruction of the EPA will result in x more babies contracting disease, y more people developing tumors and illnesses from unsafe drinking water, z more thousandths of a degree added to the acceleration of global warming.
As others have pointed out if you are trying to get a Trumpette to see the light the way not to do so is by dwelling on all the normative deficiencies of the contemporary US right. Of course those are absolutely true, but fulminating on them won't accomplish anything. Instead, we should stick to the facts of how damaging R policies are. Let the moral conclusions take care of themselves.
And yes, obviously, ensconced in their echo chamber and attached to the hate radio feeding tube very few Trumpettes will ever comprehend, let alone accept, the enormity of the holocaust they have unleashed. But by definition, if you're talking to one, in that moment they are for once talking to somebody reasonable. We can use that small window to vent our frustrations, or we can provide them with some factual information to break their programming. This is very much how you reach people in a cult, and there is a large body of lessons learned for what works and what doesn't.