Chamber of Commerce of the U.S. v. Lockyer, 364 F.3d 1154 (9th Cir. 2004)
In 2000, California enacted Assembly Bill No. 1889 (Government Code §§ 16645-16649) which, among other things, prohibits private employers “receiving state funds in excess of $10,000 in any calendar year” from using such funds to “assist, promote, or deter union organizing.” The United States Chamber of Commerce brought an action for injunctive and declaratory relief challenging the statute on numerous grounds, including preemption under the National Labor Relations Act. The Ninth Circuit affirmed the judgment of the district court and held that the statute is preempted by federal labor law.