One of the underlying theories of the constitutional framework, as exemplified by the commerce clause, is that there shall be a free national market, unhampered by state tariffs or restrictions. Congressmen are free to ward off the rigors of disastrous foreign competition by bringing home industries under the protective umbrella of high national tariffs, but state legislators are supposed to be powerless to protect their local industries from the damaging competition--that "most potent stimulant to improvement and progress"--emanating from other states.
TAXATION -- STATE SALES TAXES IN RELATION TO INTERSTATE COMMERCE -- THE BERWIND-WHITE CASE,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol38/iss8/10