The U.S. Supreme Court case H.P. Hood & Sons, Inc. v United States in 1938 revolved around the issue of whether a state could regulate interstate commerce if it had a direct effect on public health and safety within that state's borders. The plaintiff, H.P Hood & Sons, was a milk distributor who argued that Massachusetts' law requiring all milk sold within the state to be pasteurized violated their right to engage in interstate commerce because they sourced their milk from other states as well as Canada. However, the court ruled against them stating that although Congress has exclusive authority over interstate commerce under the Commerce Clause of Constitution, this power is not absolute and can be subject to local regulations when necessary for public health or safety reasons even if these regulations might indirectly affect interstate trade.

The dissenting opinion in the case of H.P. Hood & Sons, Inc. v. United States disagreed with the majority's interpretation of Congress' power under the Commerce Clause to regulate interstate commerce. The dissent argued that while Congress has broad powers to regulate interstate commerce, it does not have unlimited authority to control all aspects of business activities within a state just because they may indirectly affect such commerce. They contended that if every local activity affecting interstate trade could be regulated by federal law, then there would essentially be no limit on federal power over states’ internal affairs - an outcome inconsistent with principles of federalism and state sovereignty enshrined in the Constitution.