“ But the immunity of interstate commerce from state taxation is not confined to what is done by the carriers in such commerce, On the contrary, it is universal and covers every class of interstate commerce, including that conducted by merchants and trading companies. And as respects the power of a state to tax property beyond its jurisdiction belonging to a foreign corporation, it is of no moment whether the corporation be a carrier or a trading company, for a state is wholly without power to impose such a tax. ”

“ It is thus manifest on the face of all of the cases that they in no way sustain the assumption that because a violation of the Constitution was not a large one it would be sanctioned, or that a mere opinion as to the degree of wrong which would arise if the Constitution were violated was treated as affording a measure of the duty of enforcing the Constitution. ”

“ That a foreign corporation is partly, or even chiefly, engaged in interstate commerce does not prevent a state in which it has property and is doing a local business from taxing that property and imposing a license fee or excise in respect of that business, but the state cannot require the corporation as a condition of the right to do a local business therein to submit to a tax on its interstate business or on its property outside the state. ”