You know that immigration is a bizarre field when the plaintiffs in an action include the U.S. Chamber of Commerce and "various civil rights organizations."
I, frankly, do not see anything wrong with Judge Roberts' analysis. The federal government allows states to make licensing decisions -- Arizona made a licensing decision. The federal government has a system to make sure you are not hiring illegal aliens -- Arizona tells employers to use that system.
Why does the Chamber of Commerce want the Arizona law struck down? Because it knows that its members hire a shitload of illegal aliens, and it knows the federal government generally cannot do much to prevent that (because, quite frankly, federal politicians are beholden to large corporate donors).
So when AZ politicians might actually start cracking down on violations of federal law by shutting down businesses? End of the world. Federal government is our friend and must control everything related to business in this regard -- a rather hilarious position for the Chamber to take.
You can count this as a HUGE victory for the Tea Baggers, who love states rights and who hate people of color. The Roberts Court, for once, makes a decision AGAINST the interests of big business, while the 4 liberal justices say "Go ahead big business, break the law all you want...."
It is really "Through the Looking Glass" stuff.