http://news.yahoo.com/s/ap/us_immigrati ... VldG9ibG8-"In our constitutional system, the federal government has pre-eminent authority to regulate immigration matters," the lawsuit says. "This authority derives from the United States Constitution and numerous acts of Congress. The nation's immigration laws reflect a careful and considered balance of national law enforcement, foreign relations, and humanitarian interests."
I haven't read the pleadings, but I wonder what provision of the US Constitution the feds are relying on. Last time I read it, there is no provision of the Constitution that gives the federal government the power over immigration. The only thing it says is that Congress has the power to establish a "uniform rule of naturalization."
I would agree that there are numerous acts of Congress, and also Supreme Court opinions establishing the power; however, it was established not based on the Constitution, but based on a concept of an inherent power of a nation.
This will be quite an interesting case.