Facts of the Case

California's Criminal Syndicalism Act prohibited advocating, teaching, or aiding the commission of a crime or unlawful acts of violence or terrorism. John Harris, a socialist, was indicted under the statute. Harris claimed the law had a "chilling effect" on his freedom of speech. After a California state court upheld Harris' conviction, a federal district court struck down the Act because of vagueness and overbreadth.

Question

Did the federal court, in stopping a prosecution in a state court, violate constitutional principles of federalism?

Conclusion

In an 8-to-1 decision, the Court held that "settled doctrines" of federalism narrowly confined the availability of injunctive relief against state criminal prosecutions. Specifically, the Court found that a federal court could not properly enjoin enforcement of a statute "solely on the basis of showing that the statute 'on its face' abridges First Amendment rights." The Court referred to "the basic doctrine of equity jurisprudence," under which federal courts were required to show proper respect for state functions and notions of comity.