In the case of Kelly v. Kosuga, the U.S. Supreme Court ruled in 1958 that a contract for future delivery of goods could not be declared void due to price-fixing allegations if both parties had already substantially performed their obligations under the agreement. The court held that while price fixing is illegal and unenforceable, it does not necessarily mean all contracts related to such activities are automatically invalid or unenforceable as well. This decision was based on principles of equity and fairness; since both parties had received substantial benefits from their deal, neither should be allowed to escape its obligations simply because they were involved in an unlawful activity at some point during their contractual relationship.

In the dissenting opinion for Kelly v. Kosuga, Justice Whittaker argued that the majority's decision to enforce a contract despite its violation of anti-trust laws was misguided. He contended that such enforcement would undermine public policy against price-fixing and other monopolistic practices, which are designed to protect consumers from unfair pricing schemes. Furthermore, he believed it was inappropriate for courts to lend their power and authority to uphold contracts that violate these important societal norms. In his view, allowing parties who engage in illegal activities to seek relief through the legal system could potentially encourage more unlawful behavior by signaling that there will be no serious consequences for breaking anti-trust laws.