He is a very persuasive speaker. He makes you feel as if he is speaking to your soul, and he understands where you are. Bill Clinton had that ability, to a degree. Trump's voice is much more soothing than Clinton's raspy one.
He has a really good sense of how to phrase the words. Just like Sinatra with song lyrics, Trump is a master of oral speaking techniques. These are the same techniques commonly used by the best preachers, televangelists,....and snake oil salesmen and charlatans.
Listen to a vintage Billy Graham or other charismatic speaker. Not for the words, but for the cadence, tonality, phrasing, pitch changes etc. Not the words. Then listen to Trump (again, not the words) and see how similar they sound in oral speaking techniques.
Thousands of preachers use the same oratory techniques. If you were raised on that style bringing the word of God, it becomes a lot easier to accept anything delivered in that style as "truth" and not think critically about it.
I first read this and thought, "you can't be serious." But, the more I think about it, maybe you're right. I don't actually watch him speak much (just can't stomach it), but this might explain why the transcripts of his speeches are absolutely ridiculous, but yet he is so persuasive to many. Interesting.