Seriously, he made GOP relevant once again. They were constantly loosing support as they weren't radical enough and couldn't propose any things people wanted from them... Before Trump announced his campaign. Now GOP members probably want to get rid of him and keep flirting with liberals but they can't do that. Trump has so high support that they can't do anything about it anymore. They need to understand that the party belongs to Trump now.
The public's support isn't enough though. None of us average joes really count even half as much as the delegates and electoral college. So if they want a tool like Jeb Bush or Marco Rubio to go to the secondary election sadly that's what they'll have.
Trump is the ultimate RINO. He changes his views too quickly to be a conservative. He has made about half a dozen different things about what to do with illegal immigrants, including saying that we can't deport them. He's a showman, not a person who can govern. http://www.cnn.com/2015/07/24/politics/trump-illegal-immigration-inconsistent/