The National Labor Relations Board (NLRB) (plaintiff) certified an international union as bargaining representative for some of the employees of the Wooster Division of Borg-Warner Corp. (defendant). Shortly afterward, the international union chartered a local affiliate. Together the unions submitted a proposed collective-bargaining agreement to the company that identified both unions as bargaining agent. The company countered with a proposal that recognized only the local union, specifically excluding the international. The company also insisted on a ballot clause requiring employees to secretly vote on the company’s last offer before the union could strike in the event of a dispute. The unions initially rejected both clauses as unacceptable and called a strike, but the company demanded both clauses as a condition of any agreement. After a strike, the local union eventually gave in and signed a contract containing both controversial clauses. Meanwhile, the international union filed charges with the NLRB, claiming that the company’s insistence on the two clauses amounted to a failure to bargain in violation of the National Labor Relations Act (NLRA). The NLRB ordered the company to cease insisting on either clause, but the appellate court affirmed only as to the recognition clause, finding the ballot clause acceptable. The Supreme Court granted review.