Sad to see the naive on this thread don't understand that the Republican party is a big tent party. You can try for a "true" conservative, but you'll never get one. Ever. Too many special interests and single issue people out there.
So go jump to another party and say hello President Hillary. If your little Constitution party ever gets over 14% of the votes in my lifetime, I'll eat my computer.
Only way too late have I come to the same conslusion as you; that the Republicans will never nominate a conservative.
But there's more to it than special interests and single-issue voters. There is also the cabal of powerful insiders who have been calling the shots for a very long time.
Simply electing the next Republican and hoping for a few crumbs to fall our way is not the answer.