Page:Joseph Story, Commentaries on the Constitution of the United States (1st ed, 1833, vol II).djvu/420

 412 an exclusion of the states. It is indeed possible, that a tax might be laid on a particular article by a state, which might render it inexpedient, that a further tax should be laid on the same article by the Union. But it would not imply a constitutional inability to impose a further tax. The quantity of the imposition, the expediency of an increase, on either side, would be mutually questions of prudence; but there would be involved no direct contradiction of power. The particular policy of the national and state system of finance might, now and then, not exactly coincide, and might require reciprocal forbearance. It is not, however, a mere possibility of inconvenience, in the exercise of powers; but an immediate constitutional repugnancy, that can, by implication, alienate and extinguish a preexisting right of sovereignty.

§ 939. It is true, that the laws of the Union are to be supreme. But, without this, they would amount to nothing. It may be admitted, that a law, laying a tax for the use of the United States, would be supreme in its nature, and legally uncontrollable. Yet a law, abrogating a state tax, or preventing its collection, would be as clearly unconstitutional; and, therefore, not the supreme law. As far as an improper accumulation of taxes on the same thing might tend to render the collection difficult, or precarious, it would be a mutual inconvenience, not arising from superiority, or defect of power on either side, but from an injudicious exercise of it.