It's a classic Alinsky tactic, used by the right to very good effect. Number 4, Make the enemy live up to its own book of rules. Trump's not smart enough to know it, but his handlers are, and in this particular case they didn't have to do anything except keep the ball rolling because it's been pretty much an own-goal by the press who bent over backward to live up to their rules in covering Trump while he broke every rule he came across, and he didn't care if he broke it, or how long it had been a rule, or how sacrosanct a rule it was, just as long as he got what he wanted. And the GOP found out that his system worked so they're like "hey, why didn't we do this a long time ago?" And his base is saying "he speaks for me, I like how he sticks it to 'the libs' or 'the illegals'" or whoever it is that's threatening their precious privilege that day. They want a bully in a bully pulpit and that's what Trump gives them.
You know, I watched that happen. I almost said something earlier today and I held back, but since you've brought it up I'll say it now. He's not worth your time. Not in any way, shape or form is he worth your time. I've quoted Leon Festinger before, the social scientist who watched as doomsday cult he was researching in the 50s doubled down on their beliefs even when the world didn't end when they were told it would end. He said:
"A man with a conviction is a hard man to change. Tell him you disagree and he turns away. Show him facts or figures and he questions your sources. Appeal to logic and he fails to see your point. We have all experienced the futility of trying to change a strong conviction, especially if the convinced person has some investment in his belief. We are familiar with the variety of ingenious defenses with which people protect their convictions, managing to keep them unscathed through the most devastating attacks.
But man's resourcefulness goes beyond simply protecting a belief. Suppose an individual believes something with his whole heart; suppose further that he has a commitment to this belief, that he has taken irrevocable actions because of it; finally, suppose that he is presented with evidence, unequivocal and undeniable evidence, that his belief is wrong: what will happen? The individual will frequently emerge, not only unshaken, but even more convinced of the truth of his beliefs than ever before. Indeed, he may even show a new fervor about convincing and converting other people to his view."
I watch as you cite supportable facts, attempt a civil dialogue - perhaps in the hope that he'll meet you halfway in his own efforts - but he's not going to. Ever. You can hold to the idea that at least someone reading you may be intrigued enough to consider your words, but if that's the case they were partly there themselves already, they've already cracked open the door. So there's that. But you're not going to convince a single solitary Trumper. They're too invested, and they're too bigoted, too racist, too xenophobic, too far gone. I have have no further use for the ones who defend Trump online. I can only see some hope in the neighbor or the friend or the family member who's big enough to admit that they made a mistake that the country will pay the price for, for years to come.