Loyalty Oaths: Established Rights
First, the courts have made it clear that loyalty oaths may not infringe on established constitutional rights. For instance, shortly after the Civil War, early cases in the application of a loyalty oath for public office challenged the constitutionality of its statutory language. One Missouri statute required public officials to attest to never having participated in activities that were connected to actions against the federal or state governments, which would have included actions in support of the Confederates.
The U.S. Supreme Court declared the law unconstitutional because it made once-legal acts illegal retrospectively (i.e., ex post facto laws) while declaring individuals guilty of crimes based on those acts (i.e., bill of attainder), in violation of Article I, Section 9, of the U.S. Constitution. Similarly, in instances of an otherwise constitutionally permissible loyalty oath, the U.S. Supreme Court held that an individual’s refusal to take the oath cannot result in a default interpretation that the individual subscribes to the nonsupport of the federal and state constitutions and believes in the overthrow of the government. According to the Court, a default interpretation of an individual’s subscription of disloyalty—without an opportunity to explain coupled with the summary dismissal from public employment—violates the individual’s due process rights.