All joking aside, Trump might achieve greater success if he was focused more on defeating Hillary than on "destroying the GOP establishment.". Particularly given that he's counting on that Establishment to raise his money and provide volunteers.
I have been very active as a grass roots Tea Party/Conservative, but also Republican. The last two candidates haven't been my first choices by a long shot (I've never been able to stand McCain), but I made hundreds (actually a thousand) calls for them.
I wouldn't lift a finger for Trump if my life depended on it. He doesn't want my support or my help and he's made that clear.
And I am happy to oblige.