Nobody's mind will ever be changed if that person does not want his/her mind changed. I changed my mind in 2015 because after 40 years of supporting Republicans I was open to listening to the arguments that Democrats were making, and looking honestly at what the Bible said. (As opposed to looking the the Bible simply to see how I could use it to prove that I was already right.) And I know others who have done likewise. But views that are immune to changing come down to what is "gut-level absolute" for a particular person. For example, when a reporter asked a certain libertarian candidate (I forget which one, but I could look it up)(OK, I looked it up. It was Rand Paul in 2011) whether he would be OK with letting people die if they had chosen not to buy health insurance but now were sick and had changed their mind, the candidate tried to come up with a diplomatic exit from the question, but some of his supporters who were standing in the background and had heard the question loudly called out, "YEAH!"
The view of a Christian and most civilized people is, I believe, that a person who makes a rash decision and repents of it should be extended mercy. The view of at least some of those Rand Paul supporters was not merciful, it was judgmental: if a person makes a poor decision, he should live with it (or die with it). But the Apostle James wrote "For judgment will be merciless to one who has shown no mercy; mercy triumphs over judgment." Any onlooker is free to choose whichever side he wants, based on what he/she considers to be an absolute bedrock article of personal faith, but I myself would choose the path of the Bible, and of mercy. And I believe now that the Republican Party has chosen the path of judgment. So we have parted ways. I am not going to change the mind of anybody who already knows that their mind will not be changed, regardless of the evidence. All I can do is state my own views, give my reasons, and let others make up their own mind. I will not hate those who disagree with me, and I will not insult them or belittle their intelligence or their character. But will continue to hold out hope that they might come around some day.
I do sincerely hope that Donald Trump is defeated in November. But if that does not happen I will still be glad to be an American, and a Christian.