In the Federal Trade Commission v. Morton Salt Co., 1947, the Supreme Court ruled in favor of the Federal Trade Commission (FTC). The FTC had accused Morton Salt Company of violating Section 2(e) of the Clayton Act by discriminating among its customers on promotional allowances. Specifically, it was alleged that Morton provided certain large chain stores with special discounts and promotions not offered to smaller independent retailers, thereby creating a competitive advantage for larger businesses. The company argued that these practices were justified due to cost differences associated with serving different types and sizes of customers. However, this argument was rejected by the court which held that such price discrimination could substantially lessen competition or create monopoly power even if there is no intent to harm competitors or actual harmful effects have been proven yet. This case set an important precedent in antitrust law as it established that potential harm to competition can be sufficient grounds for finding a violation under U.S antitrust laws.

In the dissenting opinion for the Federal Trade Commission v. Morton Salt Co., Justice Robert H. Jackson argued that the majority's decision to uphold FTC's order against Morton Salt was a departure from established legal principles and could lead to arbitrary enforcement of antitrust laws. He contended that there was no evidence showing that Morton’s pricing policy had an adverse effect on competition or created a monopoly, which are key considerations under antitrust law. Furthermore, he disagreed with the majority's view that it is unlawful for a company to offer discounts based on quantity purchased without considering whether such discounts were reasonable or discriminatory in nature. Justice Jackson also expressed concern about giving too much power to administrative agencies like FTC by allowing them to regulate business practices even when they do not harm competition.