William O. Douglas,
In re Green (369 U.S. 689) — Opinion of the Court
“ Wisconsin Employment Relations Board, supra, held, a state court is without power to hold one in contempt [1] for violating an injunction that the state court had no power to enter by reason of federal pre-emption. Even if we assume that an ex parte order could properly issue as a matter of state law, it violates the due process requirements of the Fourteenth Amendment [2] to convict a person of a contempt of this nature without a hearing and an opportunity to establish that the state court was acting in a field reserved exclusively by Congress for the federal agency. ”
