Response or Comment
Congress has exclusive power to regulate interstate commerce, so far as it admits of a uniform system of regulation, and a failure on its part to regulate in a given case is tantamount to a declaration that such commerce shall remain free and unrestricted. Brown v. Houston, 114 U. S. 622; Leisy v. Hardin, 135 U. S. 100. The states are, in all such cases, without jurisdiction to regulate, irrespective of what Congress has or has not done.
Sunderland, Edson R. "The Passing of State Control over Railway Rates." Mich. L. Rev. 9 (1911): 702-4.