That immigration efforcement is a role reserved for the Federal, not State govt. I guess one could argue if someone is breaking a federal law then state law enforcement would be obligated to “assist”, however, I don’t think SCOTUS, including Scalia, will buy that. Again, I am opposed to illegals and believe they should be deported, but I am not sure I am in favor of the AZ law.
The 10th Amendment says nothing about areas that the states can’t choose to enforce laws—only areas that the federal government can’t choose to go.
The AZ law is a state law chosen by the state and in no way is it possible for such a law to violate the 10th Amendment.