Liberal Obama Suddenly Concerned About Protecting Constitution, Sues Arizona Over SB1070

CNN.com:

The Justice Department weighed in on one of the most explosive issues in American politics Tuesday, filing a lawsuit to overturn a tough new Arizona immigration law that has sharply divided people along partisan, ideological and ethnic lines.

It also asked the federal courts to grant an injunction to stop enforcement of the measure before it takes effect late this month.

Arizona's law requires immigrants to carry their alien registration documents at all times and allows police to question the residency status of people in the course of enforcing another law. It also targets businesses that hire illegal immigrant laborers or knowingly transport them.

Justice Department lawyers argued that the state statute should be declared invalid because it has improperly preempted federal law.

"In our constitutional system, the power to regulate immigration is exclusively vested in the federal government," the brief states. 

Cherry picking Constitutional rights.