In the case of Hooker v. Knapp et al., Members of the Interstate Commerce Commission, 1911, the U.S Supreme Court was asked to determine whether a railroad company could be compelled by law to provide equal facilities for all shippers regardless of their location along its line. The plaintiff, a coal mining company located at one end of the rail line, argued that it was being discriminated against because another shipper located in between two lines received preferential treatment and lower rates due to its advantageous position. The defendants were members of the Interstate Commerce Commission who had ruled in favor of maintaining this differential pricing structure. The Supreme Court held that while there is an obligation on part of carriers under federal law (Interstate Commerce Act) to treat all shippers equally without any undue preference or advantage; however, they also recognized that absolute equality might not always be possible due to varying circumstances such as geographical conditions or business necessities which may justify some differences in service levels and charges. Therefore, each case must be evaluated individually based on its specific facts and circumstances before concluding if there has been unlawful discrimination or not.

In the dissenting opinion for Hooker v. Knapp et al., it was argued that the Interstate Commerce Commission (ICC) should have jurisdiction over intrastate commerce when it directly affects interstate commerce. The dissenting justices believed that if an act of Congress is clear and constitutional, then courts must enforce it as written rather than interpreting its meaning based on potential consequences or implications. They contended that the majority's decision to limit ICC's authority could undermine federal regulation of interstate commerce by allowing states to enact laws conflicting with national policy. Furthermore, they expressed concern about creating a precedent where courts can override legislative intent based on their own judgment of what constitutes reasonable or necessary legislation.