The Lake Carriers' Association v. MacMullan case in 1971 revolved around the constitutionality of a Michigan law that regulated water pollution from ships operating on the Great Lakes. The plaintiffs, including shipping companies and associations, challenged this state law arguing it was unconstitutional as it interfered with interstate commerce and conflicted with federal laws governing navigation. However, the Supreme Court upheld the validity of Michigan's statute by a unanimous decision. The court ruled that states have authority to enact environmental regulations for waters within their jurisdiction unless such rules directly conflict with federal statutes or impede foreign or interstate commerce excessively. It concluded that there was no significant interference in either area; hence, Michigan's anti-pollution measures were not unconstitutional.

In the dissenting opinion for Lake Carriers' Association v. MacMullan, Justice Blackmun argued that the majority's decision to uphold Michigan's ballast water statute was incorrect because it violated the Commerce Clause of the U.S. Constitution. He contended that this law unfairly burdened interstate commerce by imposing additional costs on out-of-state vessels while exempting in-state ones from similar requirements. Moreover, he believed that such a state regulation could potentially lead to inconsistent and conflicting rules across different states, thereby creating an unstable regulatory environment for interstate shipping companies. Furthermore, he asserted that Congress had already established comprehensive regulations governing ship pollution under federal laws like The Federal Water Pollution Control Act and The Refuse Act of 1899; therefore, allowing individual states to enact their own separate standards would undermine these existing federal frameworks.