In the case of Minnesota v. Clover Leaf Creamery Co., 1980, the Supreme Court ruled in favor of a Minnesota law banning non-returnable, non-refillable milk containers to promote conservation and ease solid waste disposal problems. The court held that this statute did not violate either the Equal Protection Clause or the Commerce Clause of the Constitution. Clover Leaf Creamery and other dairy businesses had argued that it unfairly discriminated against interstate commerce since most plastic milk jugs were manufactured out-of-state while most paperboard cartons were produced within Minnesota. However, Justice Brennan wrote for a unanimous court stating that states may enact laws with incidental effects on interstate commerce if they are rationally related to legitimate state interests - in this case environmental protection.

In the dissenting opinion for Minnesota v. Clover Leaf Creamery Co., Justice Brennan, joined by Justice Marshall and Justice Blackmun, argued that the majority's decision was flawed because it failed to properly apply the Commerce Clause analysis. They contended that Minnesota’s ban on plastic nonreturnable milk containers while allowing paper ones constituted a form of economic protectionism which violated the Commerce Clause of the U.S Constitution. The dissenters believed that this law favored in-state interests (paper container manufacturers) over out-of-state competitors (plastic container manufacturers). Furthermore, they disagreed with majority's conclusion about environmental benefits from banning plastic containers as speculative and unsupported by substantial evidence. In their view, if such discriminatory laws were allowed under mere speculation or conjecture about possible local benefits without solid proof then it would undermine interstate commerce principles enshrined in constitution.