In the case of Alabama Public Service Commission et al. v. Southern Railway Co., 1950, the U.S Supreme Court ruled in favor of Southern Railway Co., reversing a decision by the Alabama Public Service Commission that had ordered an increase in intrastate freight rates to match those set federally for interstate commerce. The court held that while states have authority over their own internal affairs, they cannot interfere with or obstruct federal regulation of interstate commerce under the Commerce Clause of the Constitution. This ruling affirmed that state regulatory bodies do not have jurisdiction over matters pertaining to interstate trade and transport rates as these are within federal purview.

In the dissenting opinion for Alabama Public Service Commission et al. v. Southern Railway Co., it was argued that the Supreme Court overstepped its jurisdiction by interfering with a state's power to regulate its own internal commerce, in this case, intrastate railroad rates set by Alabama's Public Service Commission. The dissenters contended that there was no violation of federal law or constitution and thus, no grounds for federal intervention. They emphasized that states have sovereignty over their local affairs unless they infringe on national interests as defined by Congress - not the courts. Furthermore, they criticized the majority’s reliance on past cases involving interstate commerce which were irrelevant to this case about intrastate business regulation.