Because Trump is the only candidate upholding Rule of Law, including the existing immigration laws. Neither the Republican nor Democrat parties are doing so.
I don’t think this guy can be boxed in. TRUMP would not go after guns, abortion, gay marriage,etc...he is inspired by jobs, economy,trade. My best guess. I imagine him “getting the best around him” and heeding wisdom most of the time. If he puts Palin or Cruz in...that will tell the story. In many ways he is our insurance policy against the GOP machine.