The U.S. Court of Appeals for the Ninth Circuit rejected a union’s constitutional challenge to the National Labor Relations Board’s ruling that it had engaged in unlawful secondary picketing.

As the Ninth Circuit observed, under the National Labor Relations Act, a union may not “induce or encourage” employees of a neutral employer to strike against that secondary employer in order to provide greater leverage in the union’s dispute against the primary employer. The Supreme Court in the 1951 case of Int’l Brotherhood of Electrical Workers v. NLRB (IBEW), found that peaceful picketing violated this prohibition and that the prohibition “carries no unconstitutional abridgement of free speech.”

In NLRB v. Int’l Ass’n of Bridge, Structural, Ornamental and Reinforcing Workers, Local 229, a union business agent spoke to, texted, and gave flyers to the employees of a neutral employer in order to persuade them to engage in a secondary boycott of their employer in support of the union’s dispute with a fellow subcontractor. The union argued that IBEW was limited to picketing activity, and that its speech activity was protected by the First Amendment right to free expression. The Ninth Circuit disagreed, finding “the words ‘induce and encourage’ broad enough to include every form of influence and persuasion.” Joining two other sister circuits that had previously addressed this issue, the Ninth Circuit found that the “First Amendment is not at all implicated” in the Act’s prohibition on secondary boycott activities.