I wasn’t specifically thinking about the Shreveport Rate Case. There are plenty enough instances of the feds lording it over the railroads for me to bypass specific instances. And in Houston E & WT Railroad Co. I think they might have relied on the necessary and proper clause (as in controlling intrastate rates was necessary to prevent the bogey of “predatory pricing “ on the interstate level). Perhaps without Gibbons they never would have dared use necessary and proper in that manner. We’ll never know.
Shreveport strikes me as reasonable. What they were doing seems to fall into the category of ‘contrivance’. Madison anticipated that.