The U.S. Supreme Court case Willcox et al., Constituting the Public Service Commission of New York, v. Consolidated Gas Company in 1908 revolved around a dispute between the state's public service commission and a gas company over rate regulation. The court ruled that states have the right to regulate utility rates within their jurisdiction as long as those rates allow for reasonable profit for companies providing services. This was based on the principle that utilities are affected with a public interest due to their monopolistic nature and essential role in society, thus justifying government intervention in setting prices to protect consumers from potential abuses of monopoly power while ensuring fair returns for providers.

In the dissenting opinion for Willcox et al., Constituting The Public Service Commission of New York, v. Consolidated Gas Company, Justice Harlan argued that the court majority had overstepped its authority by substituting its judgment for that of a state legislature in determining what constitutes a reasonable rate of return on investment for public utilities. He maintained that it was not within the purview of courts to decide whether rates set by legislative bodies were fair and just; rather, their role should be limited to ensuring due process is followed in setting those rates. Furthermore, he contended that if every case involving rate regulation were brought before federal courts as constitutional issues, it would lead to an impractical and unmanageable situation where courts become regulatory agencies themselves instead of focusing on legal matters.