And it’s far from clear to what’s going to happen. Thomas, ordinarily the staunchest states’ “rights” justice, is different in preemption. And elite Republicans don’t have monolithic views on immigration enforcement (in particular, you have to think that Kennedy might see auto executives getting detained in Alabama and think it might be time to put the brakes on.) But the Supreme Court always likes a chance to overrule the 9th Circuit and while Noonan — one of the 9CA justices who voted to strike the law — is a conservative his views on federalism are comparable to Breyer’s, so it doesn’t really tell us anything.
Another possibility I didn’t discuss in the Guardian piece is that the Supreme Court could follow the 9CA dissenter, who voted to uphold some but not all of the law. Carlos Bea would have struck down only the provision that would have made it a state crime not to carry papers and the clause that makes it illegal for an undocumented immigrant to seek work, while upholding the rest (including the crucial “show us your papers” arbitrary search provision.) I could see that appealing to Roberts in particular. But it’s hard to read the tea leaves on this one, particularly for such a potentially important case.