CBS confirms the slip from Hillary Clinton. The Obama DoJ will sue the state of Arizona for enforcing immigration laws:

Now a senior administration official tells CBS News that the federal government will indeed formally challenge the law when Justice Department lawyers are finished building the case. The official said Justice is still working on building the case.
Contacted about Clinton’s comments today, State Department spokesman PJ Crowley said they reflected her beliefs.
“The Secretary was asked about the Arizona law during a TV interview in Ecuador,” he said. “She believes that a better approach is comprehensive immigration reform, and said so. Regarding how far along the legal review is, that is a matter for the Department of Justice.”
The Arizona law, which would go into effect in July, requires immigrants in the state to carry documents verifying their immigration status and requires police officers to question a person about his or her immigration status during a “lawful stop” if there is “reasonable suspicion” that person may be in the country illegally.