There are two kinds of elected Republican Trump supporters; those that need him, and those that fear him. Some politicians are both. Most don’t necessarily agree with his policies, or frankly, can even tell you what they are. He’s a registered Republican and so are they. For most, that’s where the commonality ends.
For private citizens however, there is one main reason they are Trump supporters. It’s not because they fear him, they don’t need him to get elected or raise money, and they probably can’t tell you much about his policies either. For them it’s not so much the what or why he does what he does, it’s the how he does it.
Trump’s appeal to his base is his no holds barred, nonpolitically correct (sometimes even morally correct), off-the-cuff, cut-throat, borderline bullying at times, demand for what he wants done, and when he wants it. He has fired some of the most powerful people on the planet in a tweet. (The best people)
He is not a diplomat. He’s honestly (despite his claims otherwise) not even a good negotiator. He simply makes demands, and you either abide by them, or you don’t. If you don’t, you pay the price. Love him or hate him, he is who he is, and half the nation has signed off on accepting him that way after 4 years of watching him in action.