Ironically only the day before, the American Civil Liberties Union filed a constitutional challenge to Sen. Delph's bill. The Indiana Law Blog has links to the complaint as well as other documents related to that filing.
|State Senator Mike Delph|
Having said that, I did not agree with those opponents to Delph's bill who were absolutely certain that states were barred from passing laws on immigration.
The Constitution contains a list of matters that Congress can legislate on. Most of those matters are outlined in Article I, Section 8, the so-called enumerated powers. Any law passed by Congress is is supposed to relate to a specific power granted to the federal government by the Constitution..
State power works just the opposite. Unless there is a provision in the U.S. (or state) Constitution, denying certain power to the state, the state can exercise that power and pass a law on the subject.
If you sketch out these two concepts, you'll find an area where the federal and state governments have overlapping power. In that area, states can still pass laws, but the validity of those laws is governed by the Supremacy Clause. The issue of immigration falls within that area of overlapping powers.
In reviewing the impact of the Supremacy Clause, the first thing you look at is whether the federal government has "preempted" the area. "Preemption" is a fancy word that means that the federal government has completely taken over the area and no state legislation on the subject will be allowed. Preemption is determined by looking at the legislative intent of Congress as well as the pervasiveness of the regulation. An example of an area that has been preempted by the federal government is the regulation of the airline industry.
Even if the federal government is not determined to "preempt" the area the state law still might not be valid. The issue in this analysis is whether the specific state law conflicts with federal law on the same subject.
These are the issues the United States Supreme Court was wrestling with in Chamber of Commerce v. Whiting. Those who were certain that it was a slam dunk issue, that only the federal government can legislate on immigration, well that was never the case at all. One can question whether Delph's bill is good policy, but almost certainly, after Whiting, they can't say it is unconstitutional.