In Truax v. Corrigan (1921), the Taft Court struck down an Arizona law that prohibited courts from issuing injunctions to prohibit picketing of businesses arising out of labor disputes. Former cooks and waiters of the English Kitchen, a restaurant in Bisbee, Arizona, picketed the store and implored would-be patrons not to enter the restaurant. As a result of the picketing campaign, the business suffered a large loss in revenue, making $12,000 instead of its normal rate of more than $50,000.

The restaurant owner sought an injunction from a court in order to prohibit the picketing campaign. However, an Arizona state law provided that “no restraining order or injunction shall be granted by any court of this state … in any case between an employer and employees … or growing out of a dispute concerning terms and conditions of employment.”

The restaurant owner contended that the statute violated the Due Process and Equal Protection clauses of the Fourteenth Amendment. He argued that the law violated due process because it prohibited a court from protecting the property and value of the business, an important property right. He also argued that the law violated equal protection because it prohibited injunctions against picketing by employees or ex-employees and not picketing by other individuals, such as competing restaurant owners.

The Court ruled 5–4 that the statute violated both due-process and equal-protection principles. Focusing on the concerted campaign, which included picketing and allegedly libelous statements about restaurant management, the Court ruled that the statute did deprive the owner of the restaurant of his property. “To give operations to a statute whereby serious losses inflicted by such unlawful means are in effect made remediless, is, we think, to disregard fundamental rights of liberty and property and to deprive the person suffering the loss of due process of law,” Chief Justice Taft wrote for the majority.

Taft also reasoned that the law violated equal protection, because it singled out for protection a particular form of picketing. He determined that the effect of the Arizona law was to allow “direct invasion of the ordinary business and property rights of a person” by ex-employees only. “If this is not a denial of the equal protection of the laws, then it is hard to conceive what would be,” he wrote.