While the United States Supreme Court has in recent years held that the states have wide powers under the Fourteenth Amendment to regulate labor relations, it has during the same period circumscribed state authority over matters falling within the purview of Title I of Taft-Hartley viz., the National Labor Relations Act.
Donald H. Wollett,
Taft-Hartley and State Power to Regulate Labor Unions,
30 Wash. L. Rev. & St. B.J.
Available at: https://digitalcommons.law.uw.edu/wlr/vol30/iss1/1