He will be the GOP nominee, but only because he won the delegates. The very best we can expect is that Trump will get "lip service" support from the GOP, but NOTHING tangible in the way of support whatsoever. No "get out the votes". No local support. Trump will be pretty much on his own.
The whole attitude will be "Yeah, he's the nominee, but he's not really someone we can support."
They certainly expected all of us to support their faux conservative candidates for the last 26 years though, didn't they. The slaves have left the plantation and we will never forget.