In the case of Colorado v. United States et al., 1925, the state of Colorado sought to prevent the enforcement of an order by the Interstate Commerce Commission (ICC) that would allow a railroad company to abandon two intrastate branches. The Supreme Court ruled in favor of ICC and against Colorado, stating that while states have power over their internal commerce, this does not extend to matters which affect interstate commerce or national concerns. The court held that railroads are instrumentalities of interstate commerce and therefore subject to regulation by Congress under its constitutional authority over such commerce. Thus, even though these were intrastate branches, they were part of an overall system engaged in both intra- and interstate business; hence federal jurisdiction was applicable here.

In the dissenting opinion for Colorado v. United States et al., Justice McReynolds disagreed with the majority's decision to allow federal control over intrastate rail lines, arguing that it was a violation of states' rights. He contended that the Interstate Commerce Commission (ICC) did not have jurisdiction over purely internal state matters and its attempt to regulate them was unconstitutional. The justice argued that allowing such federal intrusion into state affairs would set a dangerous precedent, undermining the balance between state and federal powers established by the Constitution. Furthermore, he expressed concern about potential misuse of this power by future administrations if left unchecked.