The U.S. Supreme Court has upheld a key component of Arizona’s controversial anti-immigrant law while striking down three other provisions. In a long-awaited decision Monday, the court rejected S.B. 1070’s rules subjecting undocumented immigrants to criminal penalties for seeking work or failing to carry immigration papers at all times. In each case, the majority said those powers rest with the federal government, not with Arizona. But in a unanimous decision, the justices upheld the law’s controversial Section 2B, which requires police to check the immigration status of people they stop before releasing them. In a statement, the American Civil Liberties Union said the decision “will lead to widespread civil rights violations until it is reviewed again and possibly struck down.”