The U.S. Supreme Court case J.W. Hampton, Jr., & Company v. United States in 1927 revolved around the issue of delegation of legislative power to the executive branch and whether it violated the Constitution's separation of powers principle. The plaintiff, a private company, challenged an act that allowed the President to adjust tariff rates if he found them unequal from country to country after investigation by Tariff Commission. The court ruled in favor of the government stating that as long as Congress provides an "intelligible principle" guiding its delegated authority, such delegation is constitutional under Article I Section 1 - also known as non-delegation doctrine - which states all legislative powers are vested in Congress alone. This ruling established what came to be known as “the intelligible principle rule” for evaluating delegations of regulatory power.

In the case of J. W. Hampton, Jr., & Company v. United States (1927), Justice James Clark McReynolds dissented from the majority opinion which upheld Congress's delegation of tariff-setting powers to the President as constitutional under a "flexible tariff" law. In his dissenting opinion, Justice McReynolds argued that this was an unconstitutional delegation of legislative power by Congress to the Executive branch and violated separation-of-powers principles enshrined in the Constitution. He contended that setting tariffs is inherently a legislative function and should not be delegated to another branch without clear guidelines or standards for its exercise; otherwise it would lead to arbitrary decision-making by executive officials with no accountability or oversight mechanism in place.