The problem is he is telling a message that just is not true. In the past, what's worked for him is to lie about something enough, that people will just start thinking it's true. Like 4-5 months ago when he said the recession was over.
He keeps saying the other side has offered no ideas, and wants to do nothing about the problems of the US, and that's just a lie. It's not a misconception on his part, it's a bold face lie.
This kind of stuff, over the long haul, just does not help you. He is going down hill fast.