In the case of Liggett & Myers Tobacco Co. v. United States in 1936, the U.S Supreme Court upheld a lower court's ruling that found several large tobacco companies guilty of violating antitrust laws by colluding to control prices and stifle competition. The defendants, including Liggett & Myers Tobacco Company, argued that their actions were not illegal because they did not result in unreasonable restraints on trade or commerce as prohibited under the Sherman Act. However, the Supreme Court disagreed with this interpretation and affirmed that any form of price-fixing constituted an unlawful restraint on trade regardless if it was reasonable or not. This decision reinforced federal authority to regulate business practices for protecting competitive markets and consumer interests.

In the dissenting opinion for Liggett & Myers Tobacco Co. v. United States, Justice McReynolds argued that the majority's decision to uphold a federal law prohibiting price discrimination was an overreach of congressional power under the Commerce Clause. He contended that Congress had no authority to regulate local transactions or prices and believed this case did not involve interstate commerce in any substantial way. Furthermore, he criticized the majority for their broad interpretation of "unfair competition," arguing it could potentially criminalize normal business practices and stifle competition rather than promote it as intended by antitrust laws. Ultimately, Justice McReynolds expressed concern about potential government intrusion into private businesses' affairs and warned against expanding federal powers beyond constitutional limits.