Interstate commerce being a federal power under the Constitution prohibits states acting to regulate interstate commerce where the federal government has acted, without the permission of Congress, and prohibits the States from discriminating against out-of-state commerce generally. That doesn&#x27;t mean that all State regulation of interstate commerce is prohibited, but the State&#x27;s power is sharply circumscribed by the mere designation of the federal power as well as by federal action exercising that power.