Trump is not a particularly good public speaker / rhetorician, especially if you look at his impromptu remarks. If you took the advice of Republican pundits like Newt Gingrich or Frank Luntz and dumbed them down to a third-grade level, you'd get Trump. He often repeats the same opinion three times in a row, and the tactic seems to work. "Fool me once, shame on you. Fool me twice, shame on me. Fool me three times, I guess you must be right!" You won't find this method listed in any classic texts on rhetoric. That's because until now, nobody thought that listeners were that stupid.
Two factors I'd add to your list:
1. Trump did not create his base; he exploited it. The "demand" for a figure like Trump was already in the air (during the 2016 campaign, many supporters said something like "he says what we feel"); Trump simply tapped into it (the birther nonsense was his toe in the water--not only did it gain him an audience of underthinkers, it brought him a raft of free media attention, and it does to this day). That Trump was already planning for this strategy is evident from the fact that his bedside reading (according to Ivana Trump) was the speeches of Hitler--not Mein Kampf, just the speeches.
2. Trump had his own Leni Rieffenstahl in the staff of Fox News. Whenever Trump made a verifiable error (not necessarily a lie or a distortion, just a statement that was provably false), Fox News would bring on some pseudo-expert to show that the error was not an error at all. Even Sarah Palin didn't get this much leeway from Fox. The effect has been so powerful that now Trump can claim that Fox itself (not just its newscasters but its polls) is false, and his fans will nod their tiny bobbleheads in agreement, even though Fox is their sole source of news outside of social media.
Charisma is not inherently a bad thing, although the unsourced lists of charismatic leaders provided here tends to restrict itself to tyrants. Martin Luther King, Jr. had charisma, Malcolm X as much or more so. Within his fairly narrow circle of supporters, Bernie Sanders was incredibly persuasive. King, Malcolm, and Sanders all used their gifts (the original meaning of the Greek term) to promote the good of their audience, not themselves. Compared to the "charismatic" autocrats listed here, or the democratically-inclined leaders who have used rhetoric and personality to benefit others, Trump is strictly bottom shelf. But so, apparently, are about 40% of the American electorate.
