From Article I, Section 8:
Originally Posted by Hershmeister
The Congress shall have power to lay and collect taxes, duties, imposts and excises, to pay the debts and provide for the common defense and general welfare of the United States; but all duties, imposts and excises shall be uniform throughout the United States;
To regulate commerce with foreign nations, and among the several states, and with the Indian tribes;
The eighteenth article of amendment to the Constitution of the United States is hereby repealed.
The transportation or importation into any state, territory, or possession of the United States for delivery or use therein of intoxicating liquors, in violation of the laws thereof, is hereby prohibited.
This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by conventions in the several states, as provided in the Constitution, within seven years from the date of the submission hereof to the states by the Congress.
Note that Section 2 clearly carves out an exception to the so-called "commerce clause". That exception was deemed necessary in order to secure ratification -- or at least to provide political cover for some of its advocates. It also has the curious effect of making a violation of state law a federal crime. I don't know whether any Federal legislation has ever established penalties, however.