SAN FRANCISCO (AP) — Medical marijuana advocates are suing to put a stop to a federal crackdown on California pot dispensaries, claiming the effort by the state's four U.S. attorneys is unconstitutional.Attorneys for patients and dispensaries pushed Monday for a temporary restraining order halting threatened arrests.The lawsuit filed Friday accuses the Department of Justice of entrapping pot providers by reversing its own policy.Plaintiffs cite a 2010 agreement in which a Santa Cruz County medical marijuana cooperative agreed to dismiss its case against the federal government because the department told U.S. attorneys to defer to states on medical use of the drug.The state's four federal prosecutors last month announced a broad effort to close pot clubs, telling landlords who rent space to pot dispensaries they could have their property seized.