This mode of reasoning appears sometimes to turn upon the supposition of usurpation in the national government; at other times it seems to be designed only as a deduction from the constitutional operation of its intended powers. It is only in the latter light that it can be admitted to have any pretensions to fairness. The moment we launch into conjectures about the usurpations of the federal government, we get into an unfathomable abyss, and fairly put ourselves out of the reach of all reasoning. Imagination may range at pleasure till it gets bewildered amidst the labyrinths of an enchanted castle, and knows not on which side to turn to extricate itself from the perplexities into which it has so rashly adventured. Whatever may be the limits or modifications of the powers of the Union, it is easy to imagine an endless train of possible dangers; and by indulging an excess of jealousy and timidity, we may bring ourselves to a state of absolute scepticism and irresolution. I repeat here what I have observed in substance in another place, that all observations founded upon the danger of usurpation ought to be referred to the composition and structure of the government, not to the nature or extent of its powers. The State governments, by their original constitutions, are invested with complete sovereignty. In what does our security consist against usurpation from that quarter? Doubtless in the manner of their formation, and in a due dependence of those who are to administer them upon the people. If the proposed construction of the federal government be found, upon an impartial examination of it, to be such as to afford, to a proper extent, the same species of security, all apprehensions on the score of usurpation ought to be discarded.
It should not be forgotten that a disposition in the State governments to encroach upon the rights of the Union is quite as probable as a disposition in the Union to encroach upon the rights of the State governments. What side would be likely to prevail in such a conflict, must depend on the means which the contending parties could employ toward insuring success. As in republics strength is always on the side of the people, and as there are weighty reasons to induce a belief that the State governments will commonly possess most influence over them, the natural conclusion is that such contests will be most apt to end to the disadvantage of the Union; and that there is greater probability of encroachments by the members upon the federal head, than by the federal head upon the members. But it is evident that all conjectures of this kind must be extremely vague and fallible: and that it is by far the safest course to lay them altogether aside, and to confine our attention wholly to the nature and extent of the powers as they are delineated in the Constitution. Every thing beyond this must be left to the prudence and firmness of the people; who, as they will hold the scales in their own hands, it is to be hoped, will always take care to preserve the constitutional equilibrium between the general and the State governments. Upon this ground, which is evidently the true one, it will not be difficult to obviate the objections which have been made to an indefinite power of taxation in the United States.