He has benefitted from the primary process by garnering 46% of the delegates with 37% of the vote but now it is all "cheating and rigged," when it is his own fault for not having a ground game. He can't manage a country if he can't manage a primary season. He is very off-putting.
So that explains why a political neophyte (Donald Trump) became the GOP frontrunner!
And the fact that Donald Trump remains the frontrunner, even in the face of a systematic, slanted, and propaganda-saturated campaign of character assassination, is further tribute to his "ill-preparedness".
I guess Ted Cruz and others were even more ill prepared at actually getting the support of GOP voters...