This is the first time perhaps ever there is a candidate winning who the establishment absolutely despises. Even Reagan had his supporters inside the Party, Trump has none and is turning over the tables of the moneychangers.
He is exposing the entire corrupt system.
I think there are actually many of those, most unheard of. Ron Paul had the most popular support, and I agree, he probably had more party support (he was a senator, after all) than Trump. The Trump phenomenon is totally unprecedented in US history, but I'll wager there are historical parallels.
I think the people have a sense that the system is corrupt, run by and for cronies, etc., but at the same time frustrated at having no way to even stick a wedge into it to start to break it up.
The system set the table for itself. Pigs get fat, hogs get slaughtered.
The Republican State Committees are private organizations, Trump is a private citizen. Trump has a penchant for threatening law suits. Even better would be a bunch of class action suits by the disenfranchised voters.
Laissez les bon temps rouler!