In the Hawke v. Smith case of 1919, the U.S. Supreme Court ruled that a state cannot require ratification of a federal constitutional amendment through a referendum process under its own constitution. The case arose when Roscoe R. Hawke challenged Ohio's rejection of the Eighteenth Amendment (Prohibition) via popular vote, arguing it violated Article V of the U.S Constitution which provides two methods for amending: proposal by Congress and ratification by state legislatures or conventions in three-fourths of states. The court held that this language was intended to be interpreted literally; thus, allowing citizens to directly participate in ratifying amendments would alter the balance between national and state governments designed by framers. Therefore, Ohio's use of referendum was unconstitutional as it introduced an additional step not included in Article V’s amendment procedure.

In the dissenting opinion for Hawke v. Smith, Justice Holmes argued that the Ohio Constitution's provision allowing citizens to vote on ratification of constitutional amendments was not in conflict with Article V of the U.S. Constitution. He believed that states had a right to determine their own processes for ratifying federal constitutional amendments and that this process could include direct democracy measures like referendums if so chosen by state law or constitution. Furthermore, he disagreed with the majority's interpretation of "legislatures" as used in Article V, arguing it should be understood more broadly to encompass any body within a state given legislative power under its constitution - including voters acting through referendum.