Trump has the "mad as hell" vote. I'd guess that's about 80% of US citizens. The democrats in that category are not going to switch to any of the other, more establishment, Republicans.
That percentage is my feeling as well. Very unscientific on my part, but I base it on the readers' comments in the many news articles posted on the web. Some are this far from Revolution in their comments, but the main drift is that everybody is pist off at the politicians. I hope that Trump, even if he doesn't make it, continues to galvanize that vote.