WASHINGTON (AP) - President Barack Obama criticized Arizona's tough immigration bill as irresponsible Friday and said his administration is examining whether it would violate civil rights. Obama said the federal government must act responsibly to reform national immigration law—or "open the door to irresponsibility by others." "That includes, for example, the recent efforts in Arizona, which threaten to undermine basic notions of fairness that we cherish as Americans, as well as the trust between police and their communities that is so crucial to keeping us safe," Obama said.