In De Castro v. Board of Commissioners of San Juan, the U.S. Supreme Court ruled in favor of a Puerto Rican businessman who was denied a permit to operate his business due to an ordinance that prohibited businesses from operating within 200 feet of schools or churches. The court held that this ordinance violated the Due Process Clause and Equal Protection Clause under the Fourteenth Amendment because it did not provide for any exceptions or variances, thus making it arbitrary and unreasonable. Furthermore, the court found no rational connection between this restriction and its purported purpose - protecting public morals, health or safety - as there were other types of establishments allowed within these zones which could potentially have similar effects on these interests.

In the dissenting opinion for De Castro v. Board of Commissioners of San Juan, Justice Frank Murphy argued that the majority's decision was a violation of constitutional rights and principles. He contended that Puerto Rico should not be treated differently from other U.S territories in terms of its citizens' right to due process under law. He believed that the ordinance in question, which allowed for property seizure without proper notice or hearing, violated these fundamental rights and protections afforded by the Constitution. Furthermore, he disagreed with the majority's view on Puerto Rico’s political status as an unincorporated territory; instead asserting it should enjoy all constitutional protections like any state within United States jurisdiction.