Champion v. Ames

Champion v. Ames, 188 U.S. 321 (1903), was a decision by the United States Supreme Court which held that trafficking lottery tickets constituted interstate commerce that could be regulated by the U.S. Congress under the Commerce Clause.
Background.
Congress enacted the Federal Lottery Act in 1895, which prohibited the sending of lottery tickets across state lines. The appellant, Charles Champion, was indicted for shipping Paraguayan lottery tickets from Texas to California. The indictment was challenged on the grounds that the power to regulate commerce does not include the power to prohibit commerce of any item.
Decision of the Supreme Court.
Most important in this case was that the Supreme Court recognized that Congress' power to regulate interstate traffic is plenary. That is, the power is complete in and of itself. This wide discretion allowed Congress to regulate traffic as it sees fit, within Constitutional limits, even to the extent of prohibiting goods, as here. This plenary power is distinct from the aggregate-impact theories later espoused in the Shreveport line of cases.
The 5–4 decision upholding the statute was authored by Justice John Marshall Harlan. The dissent by Chief Justice Fuller was joined by Justice Brewer, Justice Shiras, and Justice Peckham.