A good read from VT Campaign for Liberty:
First there were “Truthers” and then “Birthers” and now there are “Tenthers.” To be accurate, the “Tenthers” actually came first, since this newly-coined term (which is supposed to denote a “fringe” position and is therefore derogatory) refers to those who believe the tenth amendment to the Constitution actually means what it says, that powers not delegated to the federal government are reserved to the states. By this definition today’s “Tenthers” may consider themselves in good company since we can assume many, if not all, of the founders themselves agreed with this concept.
So long as the Tenther movement concerns itself with preserving for the states unenumerated powers, and leaves the enumerated ones for the federal government to address, it will be on solid Constitutional ground. But the idea that a state may interpose itself in an area defined as a federal responsibility, like coining money, declaring war, or dealing with illegal immigration, is on weak footing if any.
The right thing for Arizona to do is to continue to operate under its new law, and sue (or counter-sue) the United States for a court order to implement standing illegal entry laws.
It is still their job, and they shoud perform it and pay for it!