The Issue
A little reflection will suffice to show that, as a matter of fact, any regulation at all of commerce implies some measure of power to prohibit it, since it is the very nature of regulation to lay down terms on which the activity regulated will be permitted and for noncompliance with which it will not be permitted. It is also evident that when occasion does arise for an outright prohibition of an activity, the power to enact the required prohibition ordinarily must belong to the body which is vested with authority to regulate it, which in this instance is Congress.
What, then, are the outstanding differences between such conditional prohibitions of commerce and that with which this résumé deals? There seem to be three such differences. First, there is often a difference of modus operandi between the statutes already considered and those about to be considered. The former impinge upon persons or agencies engaged in interstate commerce and their activities in connection therewith, whereas the latter look primarily to things, or the subject matter, of the trade or commerce prohibited. Secondly, there is a difference in purpose between the two categories of Congressional statutes. The purpose of the acts already treated is to lay down the conditions on which a designated branch of commerce among the States may be carried on; that of the acts now to be treated is to eliminate outright a designated branch of trade among the States. In other words, whereas the former acts were, in general, preservative of the commerce which they regulated because of its value to society, the latter regard the commerce which they reach as detrimental to society. The third, and most important difference from the point of view of Constitutional Law, is the difference in relation of the two categories of acts respectively to the reserved powers of the States. The enactments of Congress already dealt with frequently intrude upon the ordinary field of jurisdiction of the States; but when they do so, it is because the acts or things which they thus bring under national control are regarded as "local incidents" of interstate commerce itself. The relation of the enactments about to be considered to the reserved powers of the States is precisely the inverse of this. Their very purpose is to reach and control matters ordinarily governed by the State's police power, sometimes in order to make State policy more effective, sometimes in order to supply a corrective to it.
The Argument Denying Congress' Power To Prohibit Interstate Commerce
The principal argument against the constitutionality of prohibitory Congressional legislation pivoted on the dual conception of the Federal System "The Federal Equilibrium". The Constitution, the argument ran, clearly contemplates two spheres of governmental activity, that of the States, that of the United States; and while the latter government is generally supreme when the two collide with one another in the exercise of their respective powers, yet collision is not contemplated as the rule of life of the system, but the contrary. And since there are these two spheres, the line to be drawn between them, in order to secure harmony instead of collision, should recognize that the objects which the National Government was established to promote are relatively few, while those which the States were retained to advance comprise the principal objectives of government, the protection of the public health, safety, morals, and welfare. The power to promote these ends is, indeed, the very definition of the police power of the States—that power for which all other powers of the States exist. Seriously to impair the police power of the States, or to diminish their autonomy in its employment, would be, in fact to remove their reason for being, and so the reason for the Federal System itself.
So while the power of Congress to regulate commerce among the States and with foreign nations is in terms a single power, in the intention of the framers it comprised two very different powers. In the field of foreign relations, the National Government is completely sovereign, and the power to regulate commerce with foreign nations is but a branch of this sovereign power. The power to regulate commerce among the States is, on the other hand, not a sovereign power except for purposes of commercial advantage; in other respects it is confronted at every turn by the police power of the States, and hence requires to be defined in relation to the known and frequently reiterated objectives of that power.
Indeed, it was urged on the authority of Madison that the power to regulate commerce among the States was not bestowed upon the National Government "to be used for * * * positive purposes," but merely as "a negative and preventive provision against injustice among the States themselves." Madison IV, Letters and Other Writings, 15 (Philadelphia, 1865). Furthermore, it is a power which was designed for the promotion and advancement of commerce, not a power to strike commerce down in order to advance other purposes and programs. Grant that the power to regulate commerce among the States is the power to prohibit it at the discretion of Congress, and you at once endow Congress with power which it may use as a weapon to consolidate substantially all power in the hands of the National Government.
Thus, if Congress may prohibit ad libitum the carrying on of interstate commerce, it may make deprivation of the right to engage in interstate commerce in any of its phases, even the right to move from one State to another, a sanction of ever-increasing efficacy for whatever standards of conduct it may choose to lay down in any field of human action; and since laws passed by Congress in pursuance of its powers are generally supreme over conflicting State laws, these standards would supersede the conflicting standards imposed under the police powers of the States. Henceforth, in effect, the police power would exist solely by "leave and license" of Congress—as "the power to govern men and things" it would be at an end; and by the same token the Federal System, which is the outstanding feature of government under the Constitution, would be at an end. In the First Employers' Liability Cases, (Howard v. Illinois Central R. Co., 207 U.S. 463 (1908)), the majority of the Court, speaking through Justice White, gave special attention to the Government's argument that though the act, in terms, governed the liability of "every" interstate carrier to "any" of its employees, whether engaged in interstate commerce or not when the liability fell, it was none the less constitutional "because one who engaged in interstate commerce thereby submits all his business concerns to the regulating power of Congress." Justice White answered: "To state the proposition is to refute it. It assumes that because one engages in interstate commerce he thereby endows Congress with power not delegated to it by the Constitution; in other words, with the right to legislate concerning matters of purely State concern. It rests upon the conception that the Constitution destroyed that freedom of commerce which it was its purpose to preserve, since it treats the right to engage in interstate commerce as a privilege which cannot be availed of except upon such conditions as Congress may prescribe, even although the conditions would be otherwise beyond the power of Congress. It is apparent that if the contention were well founded it would extend the power of Congress to every conceivable subject, however inherently local, would obliterate all the limitations of power imposed by the Constitution, and would destroy the authority of the States as to all conceivable matters which from the beginning have been, and must continue to be, under their control so long as the Constitution endures." Ibid. 502-503. See also Justice White's dissenting opinion, for himself, Chief Justice Fuller, and Justices Peckham and Holmes, in Northern Securities Co. v. United States, 193 U.S. 197, 396-397 (1904).
The Argument Asserting the Power
The thesis that the power to regulate commerce among the States comprises in general the power to prohibit it turns on the proposition stated by Marshall in his opinion in Gibbons v. Ogden, that this power is vested "in Congress as absolutely as it would be in a single government, having in its Constitution the same restrictions on the exercise of the power as are found in the Constitution of the United States. The wisdom and discretion of Congress," Marshall continued, "their identity with the people, and the influence which their constituents possess at elections, are, in this, as in many other instances, as that, for example, of declaring war, the sole restraints on which they have relied, to secure them from its abuse." 9 Wheat. 1, 196-197 (1824).