As it had announced it would do last week, the ACLU along with several other groups filed suit in federal court today, seeking to have Arizona's "papers please" legislation enjoined before it's scheduled to take effect by the end of July.
"SB 1070 is unconstitutional," asserts the complaint. "It violates the Supremacy Clause and core civil rights and civil liberties secured by the United States Constitution, including the First Amendment right to freedom of speech and expressive activity, the Fourth Amendment right to freedom from unreasonable searches and seizures, and the Equal Protection Clause guarantee of equal protection under the law."
The lawsuit notes that, "SB 1070 requires Arizona police, Arizona jails, and Arizona courts to detect, adjudge, punish, and facilitate the deportation of individuals who, in Arizona's view, are not entitled to remain in the United States. SB 1070 makes Arizona a legal island within the United States with separate immigration rules that do not apply in the other 49 states and that are contrary to and inconsistent with the federal Immigration and Nationality Act."
(You can read the ACLU's legal doc in its entirety, here.)