First off, Trump appears to be utterly addicted to the rally. Where he can bask in the attention and approval he needs so badly. That is why he wastes valuable time and resource in states that he probably already has in the bag, he is the atom bomb of attention whores.
We’ve all seen outakes of his speeches, his “punch lines” that thrill/outrage the crowd. Any of you listen to any all the way through? He doesn’t give speeches, he gives improv. He meanders about, looking for something that gets that zing! from the audience.
(If you’ve ever been involved in theatrics, if you’ve ever been onstage, even for the smallest part, you know the feeling: when the attention of the audience is focused on you, you can feel it from scalp to toenail. Juice! Some folks fear it, some folks like it, and some others cannot live without it.)
A real political pro can pull off a pre-written speech, where every line and nuance is carefully put together. It sounds as though the speaker is speaking, talking, rather than vocalizing a pre-recorded message. Trump is an amateur, he doesn’t know how to read a speech like a politician. You’ve probably seen it, where a pro gets to a line where a response is expected, and there isn’t one, or the audience responds to the line just before the punch line, upsetting the rhythm. A pro can recover, Trump is not a pro. He does not lead his audience, he probes his audience for energy, and follows it. Improv politics.
I think Trump sincerely and mistakenly believes that rallies are an effective campaign tool, that preaching to the choir over and over will expand the size of the choir. It works great to fire up the people who are already fired up, it has no useful purpose in bringing around the people who are looking for intelligence.
If he is to “turn around” his campaign, he will have to change his style, he will have to give up all that sweet, sweet ego juice for solid political practice. I don’t think he can.