[1] In the case, Yetta Stromberg was convicted for displaying a red flag daily in the youth camp for children at which she worked, and was charged in accordance with California law.

In the state trials, the charge brought up against her was in relation to a daily ceremony that took place at the summer camp on a loaned ranch near Yucaipa, California, where she worked as a teacher.

Stromberg's attorneys cited Holmes' concept of the "clear and present danger" test,[6] asserting that the circumstances of the act must be considered as part of the decision.

In a 7–2 decision, Chief Justice Hughes followed the logic of the Holmes doctrine introduced in Schenck v. United States, 249 U.S. 47 (1919), and concluded on 18 May 1931 that the broad red flag ban was too vague, and could be used to disrupt the constitutionally-protected opposition by citizenry to those in power.

In an opinion delivered by Chief Justice Charles Evans Hughes, the Court considered whether any of the three clauses of the California law,[4] were, as the applicant alleged, a violation of her constitutionally-protected rights.

The Court had previously established in a series of cases that the right of free speech is essential to liberty, and is protected by the Due Process Clause of the Fourteenth Amendment.

Upon examining the vagueness of the statute, the Court concluded that a law so indefinite as to permit the punishment of peaceful and orderly opposition exercised in accordance with legal means and constitutional imitations was "repugnant to the guarantee of liberty contained in the Fourteenth Amendment."

Prior to the trial of this case, the California Supreme Court had already deemed invalid a city ordinance that would make unlawful the public display of a red flag, emblem, etc.

The Court of Appeals found the second and third provisions of section 403a of the California Penal Code to be in compliance with the state and federal Constitutions' guarantees of freedom of speech.