The strange appeal Trump has for much of the public is he somehow sells himself as being competent. This isn't hard to do after Bush and Obama. Trump seems like someone who will work on behalf of America as a whole in general even if a few individual interests get pushed out of the way or trampled on.
It's really twisted as hell. It's a strange deal rolling the dice on essentially a Gangster President who one might hope can handle tough characters like Putin as well as he handled mafia people controlling local construction companies.
Voting for him is like going to Don Corleone for help. He will come through for you, but he will want something in return.