He basically said he felt NC shouldn't have made any laws one way or another, It does avoid being politically correct, since he stopped short of embracing anything beyond status-quo, but boy did he get heat for this?
But let's think of this from Scott Adams' 3D persuasion filter. Firstly, I'm not sure how New England or California republicans will react to it, but I'd bet real money it doesn't bother them as much as it would the southern ones. Second, what exactly is going on? If you guessed "a bunch of right-wing nuts bashing Trump for not being a bigot", I'd say you're wrong, but I'd also say a lot of people would agree with you.
See, Trump has a bit of a problem with smears that he is somehow a bigot because he doesn't want Cartel Thugs, Daesh, or Rapefugees in our country. Now don't get me wrong, I don't think he won over the SJW crowd with this, and I don't think he was trying to. In fact, I think he probably still has their collective ire, BUT, this may easily slow any "bigot" smears he gets in the future. They will be at least somewhat less sticky after this.
A risky move, but probably less risky than calling out Bush in South Carolina, and he survived THAT. We'll see how it goes, but if he gets past the primaries, this'll be a General Election win for Trump.