Huron Portland Cement Co. v. City of Detroit

The company argued that the Detroit laws were clearly unreasonable. They imposed an unfair burden on interstate commerce, and on those grounds alone, they should be found unconstitutional. The Supreme Court did not agree.

When it finally heard the case on appeal, the Court found that the Detroit laws were completely justified. Writing for the majority, Justice Stewart explained:

The ordinance was enacted for the manifest purpose of promoting the health and welfare of the city's inhabitants. Legislation designed to free from pollution the very air that people breathe clearly falls within the exercise of even the most traditional concept of what is . . . known as the police power.

The Court went further. In addition to affirming Detroit's right to regulate its air quality, Stewart asserted the government's general right to make laws protecting its citizens, even if such laws might adversely affect interstate commerce. This was true even though only the federal government could actually regulate the commerce between states:

. . . it must be borne in mind that the Constitution when "conferring upon Congress the regulation of commerce . . . never intended to cut the States off from legislating on all subjects relating to the health, life, and safety of their citizens, though the legislation might indirectly affect the commerce of the country. Legislation, in a great variety of ways, may affect commerce and persons engaged in it without constituting a regulation of it, within the meaning of the Constitution."