the relations between the State and national governments, we should not have any difficulty in understanding them. There is no declaration that the regulations shall be made either wholly by the State legislatures or wholly by Congress. If Congress does not interfere, of course they may be made wholly by the State; but if it chooses to interfere, there is nothing in the words to prevent its doing so, either wholly or partially. On the contrary, their necessary implication is that it may do either. It may either make the regulations, or it may alter them. If it only alters, leaving, as manifest convenience requires, the general organization of the polls to the State, there results a necessary co-operation of the two governments in regulating the subject. But no repugnance in the system of regulations can arise thence; for the power of Congress over the subject is paramount. It may be exercised as and when Congress sees fit to exercise it. When exercised, the action of Congress, so far as it extends and conflicts with the regulations of the State, necessarily supersedes them. This is implied in the power to "make or alter." . . .
The peculiarity of the case consists in the concurrent authority of the two sovereignties, State and National, over the same subject-matter. This, however, is not entirely without a parallel. The regulation of foreign and interstate commerce is conferred by the Constitution upon Congress. It is not expressly taken away from the States. But where the subject-matter is one of a national character, or one that requires a uniform rule, it has been held that the power of Congress is exclusive. On the contrary, where neither of these circumstances exists, it has been held that State regulations are not unconstitutional. In the absence of congressional regulation, which would be of paramount authority when adopted, they are valid and binding. . . .
Here, then, is a case of concurrent authority of the State and National governments, in which that of the latter is paramount. . . .
. . . The State may make regulations on the subject; Congress may make regulations on the same subject, or may alter or add to those already made. The paramount character of those made by Congress has the effect to supersede those made by the State, so far as the two are inconsistent, and no farther. There is no such conflict between them as to prevent their forming a harmonious system perfectly capable of being administered and carried out as such. . . .
As a general rule, it is no doubt expedient and wise that the operations of the State and national governments should, as far as practicable, be conducted separately, in order to avoid undue jealousies and jars and conflicts of jurisdiction and power. But there is no reason for laying this down as a rule of universal application. It should never be made to override the plain and manifest dictates of the Constitution itself. We cannot yied to such a transcendental view of State sovereignty. The Constitution and laws of the United States are the supreme laws of the land, and to these every citizen of every State owes obedience, whether in his individual or official capacity. . . .
The greatest difficulty in coming to a just conclusion arises from mistaken notions with regard to the relations which subsist between the State and national governments. It seems to be often overlooked that a national constitution has been adopted in this country, establishing a real government therein, operating upon persons and territory and things; and which, moreover, is, or should be, as dear to every American citizen as his State government is. Whenever the true conception of the nature of his government is once conceded, no real difficulty will arise in the