If I had to summarize their argument for him? "I believe he'll do the things he says he'll do that I like, but not the things he says he'll do that I don't like. I'll focus on the aspects of his presidency that I liked, but not the ones I hated. He'll listen to the people currently around him that I respect, despite who he surrounded himself with his first term, and he won't listen to the people I don't like."
It's possible a second term could be great, it's possible it could be awful, and anything in between. But there's not a single reason to listen to any new promises he's made this time around and believe he'll stick with them, or to think anyone around him now will still be around him a year from now. Previously, he listened to men like
Sessions and Fauci and Bannon.
If he wins, I hope y'all's optimism is right, but he's proven himself to be untrustworthy over and over again, so you'll have to excuse natural skepticism. I get the argument that he's less likely to get us into a new war than Harris, who's actively embracing a Cheney worldview, but that's the only point I'll concede. His words are worthless if he can't be trusted.