There are now three wings in the GOP that are now engaged in a massive power struggle for the soul of the GOP. That's why this convention is a mess.
The first wing is the classic, country club GOP establishment that includes the likes of McCain, Romney, Boehner, ect ect
The second wing is the traditional conservatives like Rand and Ron Paul, Cruz, Lee, ect ect
The third and new wing is the Progressive Nationalist Populists led by Mr Trump. The first two vehemently oppose this wing of the GOP but for different reasons. And this last wing, like the other two, want to become dominate. So there is a war for the future of the GOP. To some degree it's also happening in the Democrat party but most of the Bernie voters will either stay home in Nov or get behind Hillary