I don't know about the pardon bit but I have said Trump may pull out if it looks like he can't win to avoid the humiliation of losing, it would be a huge blow to his ego to lose so by pulling out he would be spared that.
While people can question the polls what will be telling is the turn out at his rallies, the Tulsa one was a flop and we saw how deflated Trump was after that. More rallies like that, Trump may get a better sense that he may well indeed lose.
