The U.S. Supreme Court case Hawke v. Smith, in 1919, revolved around the issue of whether a state could require its legislature to ratify an amendment to the federal constitution via popular referendum. The Ohio General Assembly had ratified the Eighteenth Amendment (Prohibition), but this was challenged by Roscoe C. Hawke on grounds that Ohio's Constitution required such decisions be put to a public vote before being enacted into law. The Supreme Court ruled against Smith, Secretary of State of Ohio, stating that Article V of the U.S Constitution does not provide for or allow states to condition their legislative approval on a popular vote; it only requires consent from three-fourths of all states' legislatures for amendments to become effective. Thus, they found that requiring ratification through referenda would alter Article V’s process and infringe upon federal supremacy. This decision established important precedent regarding constitutional amendment procedures and reinforced principles related to separation between state and federal powers.

In the dissenting opinion for Hawke v. Smith, Justice Holmes argued that the Ohio Constitution's provision allowing citizens to veto legislative acts through a referendum should also apply to federal constitutional amendments proposed by state legislatures. He contended that since states have discretion in determining their own processes for ratifying amendments, they could choose to include referendums as part of this process. Furthermore, he asserted that there was no clear distinction between ordinary legislation and constitutional amendment ratification which would prevent the use of referendums in both cases. Therefore, he disagreed with the majority's decision invalidating Ohio voters' rejection of the Eighteenth Amendment through a referendum.