The Wisconsin Supreme Court affirmed the circuit court's enforcement of an order obtained by the Kohler Company from the Wisconsin Employment Relations Board enjoining the appellant union, as a violation of the "Wisconsin Employment Peace Act, from further engaging in mass picketing, coercion, and other activities, which were also unfair labor practices under the amended National Labor Relations Act, to which the Kohler Company was subject. On appeal to the United States Supreme Court, held, affirmed, three justices dissenting. While, as a general matter, a state may not, in furtherance of its public policy, enjoin conduct which has been made an unfair labor practice under the federal statutes, an injunction based on the dominant interest of the state in preventing violence and property damage can properly be granted. The dissenting justices maintained that a state cannot duplicate an administrative remedy prescribed by Congress reaching identical conduct. United Automobile Workers v. WERB, 351 U.S. 266 (1956).
Richard E. Day,
Labor Law - Federal Pre-Emption - An Inroad Through the Violence Doctrine,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol55/iss3/10