Feds sue to block Arizona immigration law
The U.S. Justice Department has filed a lawsuit challenging the constitutionality of Arizona's tough new law targeting illegal immigrants.
The government filed the lawsuit in U.S. District Court in Phoenix on Tuesday.
The lawsuit argues that Arizona's new measure requiring state and local police to question and possibly arrest illegal immigrants during the enforcement of other laws usurps federal authority.
Tuesday's action has been expected for weeks. President Barack Obama has called the state law misguided.
Supporters say it is a reasonable reaction to federal inaction on immigration.