Justice Douglas emphasized the gap between the charge and the danger invoked to justify it. Petitioners were not prosecuted for sabotage, assassination, espionage, bomb-making, or an actual conspiracy to overthrow the Government. The record instead concerned their organization and teaching of Marxist-Leninist texts, however repugnant their political creed might be.
The majority's intent requirement, Douglas argued, dangerously made criminality depend on who speaks and what the speaker believes rather than on the words or any concrete unlawful act. Treating speech as criminal because it is spoken with revolutionary purpose risked reviving the logic of constructive treason, under which people are punished for thoughts and intentions rather than overt conduct.
Douglas maintained that the First Amendment permits suppression only when speech creates a genuinely imminent and serious danger that cannot be averted through discussion and education. Advocacy, preparation, and even morally objectionable endorsement of lawbreaking are not enough without evidence that immediate serious violence is expected or is being urged for immediate execution.
There was no record evidence that the Communist Party in the United States had sufficient numbers, strategic placement, or practical capacity to make its advocacy likely to produce violent revolution. The majority instead relied on generalized fear about world communism and judicial notice. Douglas believed that free discussion had already exposed communism's defects and that the proper remedy for its ideas was more speech, not enforced silence.
He further concluded that, if clear and present danger were relevant, it should have been submitted to the jury. The Court should not decide the critical factual question of danger without evidence and without a jury determination.