Whether the federal courts have jurisdiction to apply the mailed fist of the injunction to the settlement of strike disputes sometimes depends on whether the strike is deemed an interference with interstate commerce. Thus, the Supreme Court held in the recent case of Levering & Garrigues v. Morrin that relief must be denied a group of New York structural steel fabricators who sought to enjoin the boycott activities of the iron workers union, because " . . . the sole aim of the conspiracy was to halt or suppress local building operations as a means of compelling the employment of union labor, not for the purpose of affecting the sale or transit of materials in interstate commerce."