I have suspected something similar. Conservatives are tired of being bulldozed by the Washington D.C. cartel. When Boehner and McConnell made war on the conservatives that we sent to D.C. to represent us, we felt frustrated and powerless. With every broken promise, every slap in the face, our collective anger swelled.
Donald Trump's ability to punch back at the cartel without getting bulldozed himself has made him something of a would-be dragonslayer. Right now, all that matters is that the dragon gets slain.
At the end of most fairytales, however, the dragonslayer is celebrated for vanquishing the foe, but he doesn't get to be king.
I think Trump's positions are grounded in one non-partisan thing: he hates what Obama is doing to the country, and he hates how the Republicans in Congress are letting him run wild.
Trump sees everything he's built up for himself and his family and friends being threatened by radical leftist policies, and if Republicans are too old, too tired, too afraid, or feel to cozy to stop it, then he's going to step in and try to fix it himself.
The answer is that those on the inside get to decide on who can be inside. Trump's not qualified because they say so, and that's it.
Would Trump as President vascillate between liberal and conservative policy decisions? Maybe. Would Trump make liberal social issues his priority? Right now, he's saying we don't have time for that, and that he's running on more urgent needs. Is Trump to be believed that his Job #1 is restoring American jobs, manufacturing, security, and negotiating strength with our allies, and that he's not going to pivot left on other things once in office (like McConnell and Boehner) and abandon his campaign promises?
That's what the primary is all about.
-PJ