Page:Joseph Story, Commentaries on the Constitution of the United States (1st ed, 1833, vol I).djvu/470

 430 the militia, as may be employed in the service of the United States. Yet it is not said, that such power of government is exclusive. But it results from the nature of the power. No person would contend, that a state militia, while in the actual service and employment of the United States, might yet be, at the same time, governed and controlled by the laws of the state. The very nature of military operations would, in such case, require unity of command and direction. And the argument from inconvenience would be absolutely irresistible to establish an implied prohibition. On the other hand, congress have power to provide for organizing, arming, and disciplining the militia; but if congress should make no such provision, there seems no reason, why the states may not organize, arm, and discipline their own militia. No necessary incompatibility would exist in the nature of the power; though, when exercised by congress, the authority of the states must necessarily yield. And, here, the argument from inconvenience would be very persuasive the other way. For the power to organize, arm, and discipline the militia, in the absence of congressional legislation, would seem indispensable for the defence and security of the states. Again, congress have power to call forth the militia to execute the laws of the Union, to suppress insurrections, and repel invasions. But there does not seem any incompatibility in the states calling out their own militia as auxiliaries for the same purpose.

§ 446. In considering, then, this subject, it would be impracticable to lay down any universal rule, as to what powers are, by implication, exclusive in the general