The more I think about it, the more I’m convinced that it’s not the law itself that he finds offensive—it’s that AZ wants to actually ENFORCE it. Several states and the US has similar laws on the books, but they’ve never been enforced. At least not recently.
You nailed it. The problem isn’t the law, but that Arizona plans on paying attention to it! Immigration laws are meant to be touted every 6 years, then ignored.