In the case of Chicago, Milwaukee, St. Paul & Pacific Railroad Co. v. United States et al., 1960, the Supreme Court was asked to review a decision by the Interstate Commerce Commission (ICC). The ICC had ordered certain railroads to cease and desist from giving preferential treatment to shippers who used their own facilities for loading and unloading freight cars over those who relied on railroad facilities for such services. The court upheld this order in a unanimous decision stating that it fell within the regulatory authority of the ICC under existing law at that time - specifically Section 3(1) of the Interstate Commerce Act which prohibits undue or unreasonable preference or advantage in favor of any particular person or locality, or subjecting any particular person or locality to undue prejudice or disadvantage with respect to transportation rates and services provided by carriers subject to its jurisdiction.

In the dissenting opinion for the case of Chicago, Milwaukee, St. Paul & Pacific Railroad Co. v. United States et al., it was argued that the Interstate Commerce Commission (ICC) overstepped its authority by ordering a merger between two railroad companies without considering whether such an action would be in public interest or not. The dissenting justices believed that this decision should have been left to Congress as they are more equipped to handle matters related to economic policy and competition within industries. They also expressed concerns about potential negative impacts on smaller railroads due to increased competition from larger merged entities and questioned if this could lead to monopolistic practices in the industry which may harm consumers in terms of prices and service quality.