That the SCOTUS "will" rule the law unconstitutional is an assumption. First of all this is an amendment of an existing law, the greatest portion of the law is directed at employers.
More than that other laws crafted by AZ have been challenged in court for very similar reasons. All have been upheld! By the most Liberal court in the land, to boot.
Why such an uproar when all AZ is seeking to do, is enforce Federal law? And AZ does not determine immigration status the Feds are required to make that determination!