Vote trading in the Supreme Court. Go lightly on immigration and hammer Obamacare. That is at least one theory that explains why Roberts sided with the majority.
I think the justices all agreed on the decision, just for
very different reasons. The liberals, the usual bleeding heart reasons, and all of a sudden, they just "happened" to find constructionist religion.
The conservatives, over separation of state and federal powers issues. For better or worse, I think the conservatives just read the Constitution.
Tom Clancy's words "The Constitution was never intended to be a suicide pact" ring in my head. However, it's a no-win situation. Doing end-runs for stuff "we like" opens the door for the other side to run roughshod in even worse ways in the future.
And despite the provisions of the AZ law that did get struck down, it was the ability of AZ LEO's/LEA's to ascertain the immigration status of anyone they came into contact with in the course of their duties that PO'ed the Left and LaRaza types the worst anyway, and that stood. Realistically, AZ could pass as many tough laws as they wanted, and unless the fed.gov gets serious about the duties of the CPB/ICE and gives them teeth to locate and deport illegals, it always was more of a protest action on AZ's part anyway. It's not as if AZ was going to set up their own deportation centers back into Mexico...