Some of these people have been misled to the point where they think that ridding the Republican party of Republicans is a good idea.
Yeah I have seen that comment too--LOL. Many of the anti Establishment Tea Party group actually believe they're the majority of the Republican party, when they really represent less than 20% of the party. The other 80% of the party are the party of Lincoln & Reagan, aka Reaganites aka moderate Republicans.
If Reagan were alive and running today--he would be called a Rino, and Rush Limbaugh would have already labeled him an "Establishment candidate"--(his audience's trigger word to go out on attack.) They would have never supported him, and would have kicked him to the curb for Donald Trump. It's because they're stupid. Frankly they're so stupid they don't know they're stupid.
A very good article explaining the mentality of a Trump supporter is here. How these people took over the Republican party--is beyond any rational possible explanation, other than no one was guarding the party against Reich wing nut cases, and I think that falls squarely right into Reince Preibus's lap who let these ignoramous's take the reins. Then on the other side you had Republican politicians catering to all those Evangelicals with abortion rhetoric that sent women running from the party.
A neuroscientist explains what may be wrong with Trump supporters’ brains