In the case of Ryan v. United States, the Supreme Court of the United States held that the federal government could not impose a tax on the sale of a state-owned liquor store. The case arose when the state of California sold a liquor store to a private individual, and the federal government attempted to impose a tax on the sale. The Supreme Court held that the federal government could not impose a tax on the sale of a state-owned liquor store, as it would be an unconstitutional interference with the state's right to regulate its own internal affairs. The Court reasoned that the federal government could not interfere with the state's right to regulate its own internal affairs, and that the imposition of a tax on the sale of a state-owned liquor store would be an unconstitutional interference with that right. The Court also held that the federal government could not impose a tax on the sale of a state-owned liquor store, as it would be an unconstitutional interference with the state's right to regulate its own internal affairs.

In the dissenting opinion of Ryan v. United States, Justice Black argued that Congress had exceeded its authority under the Constitution when it passed a law allowing for criminal prosecution in federal court for violations of state laws. He believed that this was an encroachment on states' rights and violated the Tenth Amendment, which reserves all powers not delegated to the federal government to be held by either individual states or citizens themselves. Furthermore, he argued that such a law would lead to confusion as there is no uniformity between different state laws and thus could result in unequal treatment depending on where one lives. In conclusion, Justice Black asserted that Congress should have left matters concerning enforcement of state laws up to each individual state rather than passing legislation granting itself power over them.