In the case of Plumley v. Massachusetts (1894), the U.S. Supreme Court ruled in favor of a state law that prohibited out-of-state companies from selling goods directly to consumers, bypassing local merchants and wholesalers. The plaintiff, an agent for a New Hampshire company, was charged with violating this law by taking orders for his company's products while in Massachusetts without having first obtained a license as required by state statute. He argued that this restriction violated both the Commerce Clause and Fourteenth Amendment of the Constitution. The court disagreed with Plumley’s argument stating that states have power to regulate their internal commerce as long as they do not interfere with interstate commerce or infringe upon federal authority over it; thus upholding Massachusetts' licensing requirement. Furthermore, it held that such laws were designed to protect local businesses from unfair competition rather than discriminate against out-of-state firms – thereby not violating any constitutional rights under Fourteenth Amendment.

In the dissenting opinion for Plumley v. Massachusetts, it was argued that the state law prohibiting out-of-state companies from selling goods directly to consumers infringed upon interstate commerce rights protected by the Constitution. The dissenting justices contended that this law unfairly discriminated against non-resident businesses and restricted free trade among states. They believed that such a restriction could only be justified if it served a legitimate public interest, which they did not believe was present in this case. Furthermore, they expressed concern about potential negative economic consequences of allowing individual states to erect barriers to interstate commerce based on protectionist policies favoring local businesses over out-of-state competitors.