I think Republicans are always vulnerable to being called racists, sexists or bigots. A candidate who is going to win has to be careful with what they say to avoid getting that pinned on him. Trump has not been careful with the KKK interview, Mexican rapists remarks, etc. A winning candidate has to be careful that what he says cannot be misinterpreted. They have to be smart about language. Their positions should not change, i.e. opposing affirmative action, opposing illegal immigration. But they can’t leave themselves vulnerable to negative sound bite clips being pulled.
Trump speaks largely unfiltered. There is upside and downside to that. I’ll take blunt outspokenness over careful political parsing at this point, though.