The Supreme Court upheld a federal law banning the interstate shipment of “filled milk,” or milk to which skimmed milk and vegetable oil had been added, holding that the law was within the power delegated to Congress by the Commerce Clause. In its opinion, written by Justice Harlan Stone, the Court stated that ordinary economic regulations would be upheld as constitutional if they were supported by a rational basis. In a footnote, Stone suggested that certain other categories of federal laws would not enjoy the same presumption of constitutionality. Laws restricting political processes such as voting or the disseminating of political information and laws directed at “discrete and insular minorities,” wrote Stone, may be subjected to a “more searching judicial inquiry.” The note foreshadowed many of the Warren Court decisions protecting minority rights, including Brown v. Board of Education.