I think that's where a lot of the shock value of Trump is coming from. He's not a politician, he also gives no fucks, so he has no problem with letting his rhetoric get impolitic as he runs with the crowd.
His actual policy isn't some extremist right-wing of the GOP, if anything he's probably in the "middle" of the field. If you were to stick Pataki on one wing and Cruz on the other.
The exception is obviously immigration. But there, Trump is in line with the base voter of the party. It's the establishment and their politicians far out of step because they're drooling at the idea that some kind of amnesty will win the party the hispanic vote. Everybody was muddling up their immigration positions, including the ones who were closer to Trump, and it left the massive opening for Trump to jabber on about Mexicans and suddenly seize the issue and put it on the forefront, and send the former anti-immigrant candidates to scramble back and even the shamnesty ones like Rubio and Jeb? to start trying harder to mask it.
I mean, is Trump wanting to ban Islamic immigrants for a period a worse or better position than wrecking up the Middle East constantly like some "sane" candidates (Rubio, Christie, Graham, Jeb, etc.) advocate on the regular? I'm not sure if presented with the false choice I wouldn't prefer Trump's ban, especially if it could be sunsetted in the law. (And knowing the ban on American citizens returning would never hold up in court. Along with who knows how much else of it would get chopped up.)