In the case of Di Santo v. Pennsylvania, 1926, the U.S Supreme Court ruled in favor of a Pennsylvania law that required foreign steamship companies to obtain a license before soliciting passengers for overseas travel. The appellant, an agent for an Italian steamship company who was convicted under this law and fined $500, argued that it violated both the Commerce Clause and Due Process Clause of the Constitution. However, Justice Sutherland delivered the opinion of court stating that as long as state laws do not conflict with federal legislation or treaties regarding immigration or commerce with foreign nations they are valid exercises of police power. Therefore, states can regulate businesses within their borders even if those businesses involve international trade or transportation so long as such regulation does not interfere with Congress's exclusive right to regulate interstate commerce.

In the dissenting opinion for DI SANTO v. PENNSYLVANIA, Justice Oliver Wendell Holmes Jr. argued that Pennsylvania's law requiring a license to act as an employment agency was unconstitutional because it violated the Fourteenth Amendment's Due Process Clause. He believed that this clause protected an individual’s liberty to engage in any of the common occupations of life without unreasonable government interference. According to him, while states have broad power under their police powers, they cannot infringe upon these fundamental rights unless there is a clear public interest at stake and no less restrictive alternative available. In his view, Pennsylvania failed to show how its licensing requirement served such an interest or why less intrusive means would not suffice.