I would mostly agree with your assessment, trump doesn’t permit anyone in his collection of idiots that he believes is smarter than him. So either Miller is dumber than trump or he is acting like he is. Either way it is not good for any of you Americans.
You don't understand narcissism or psychopathy. And you definitely don't understand who holds the power in that dynamic. Narcissists are easily manipulated. Psychopaths love to toy with narcissists, especially when they can exploit them.
Trump has a talent for playing on people's inner resentments and charming people. That doesn't mean he's smart. He believes what he is saying, so he is very convincing to some people. Trump has his loyal base, and that makes him useful, but he has always been a puppet of someone.
Also, Trump doesn't believe anyone is smarter than he is. Common narcissistic trait... they're delusional.