dissenting:
I dissent for reasons stated in concurrence in Penn Dairies v. Milk Control Commission, ante, p. 261. The fact that Moffett Field is a federal enclave instead of a leasehold does not justify denying California the power to protect the public health by requiring milk dealers selling to the United States to receive a minimum price, a power which we have today held that Pennsylvania possesses. True, Congress is given the power “to exercise exclusive legislation” over federal areas such as Moffett Field (Constitution, Art. I, § 8, cl. 17), but that does not necessarily mean that the States, no matter what their interest or need, are absolutely without power to enact legislation, not inconsistent with Congressional policy or Constitutional dictates, which will apply in some measure to those areas which are within their boundaries. Before holding that this clause invalidates important state legislation like that now before us, especially at a time when federal activities are greatly expanding and vast areas are being acquired within the States by the federal *304government, the reasonableness and necessity of such a decision should be thoughtfully examined.
We derive much of our strength as a nation from our dual system of federal government. To promote the harmonious working of that system the general clauses of the Constitution which broadly delineate the boundaries of state and national power should be construed by appraising the respective state and national interests involved and striking a balance which gives appropriate recognition to the legitimate concerns of each government. Since those boundaries are not absolutes, the question necessarily is one of reasonableness and degree. Cf. Holmes, J., dissenting in Panhandle Oil Co. v. Knox, 277 U. S. 218, 222, and again in Springer v. Philippine Islands, 277 U. S. 189, 209-210. This is the method which we have applied in testing state regulation of interstate commerce,1 and it should govern the construction of the “exclusive legislation” clause. ' If a state is acting in matters normally within its competence, with which it is especially equipped to deal, to achieve important governmental ends such as the protection of the public health and welfare or the maintenance of orderly marketing conditions, the effects of its action should be allowed to extend into federal areas within its *305boundaries unless inconsistent with an act of Congress or the provisions or necessary implications of the Constitution. This formula allows the States to carry out important programs which must be of state-wide application to be effective and adequately recognizes the paramount character of federal power. Since we have held the comparable Pennsylvania statute does not contravene any act of Congress or the Constitution (Penn Dairies v. Milk Control Commission, supra), the instant California legislation satisfies this test.
The “exclusive legislation” clause has not been regarded as absolutely exclusory,2 and no convincing reason has been advanced why the nature of the federal power is such that it demands that all state legislation adopted subsequent to the acquisition of an enclave must have no application in the area. In waging war under modern conditions it is essential that state and national, military and civilian authorities, work together as a unit, each complementing the others. The state governments have functions to perform that are vital to the war program, including those functions pertaining to the public health. So long as there is no overriding national purpose to be served, nothing is gained by making federal enclaves thorns in the side of the States and barriers to the effective state-wide performance of those functions. Indeed both the federal government and the nation as a whole suffer if the solution of legitimate matters of local concern is thus thwarted and local animosity created for no purpose.
*306A disposition on the part of the federal government or its military arm to ignore local regulations such as the present' one is not only fraught with danger to the public health, but also may create a public feeling of distrust which itself will hamper the military effort.
If Congress exercises its paramount legislative power over Moffett Field to deny California the right to do as it has sought to do here, the matter is of course at an end. But until Congress does so, it should be the aim of the federal military procurement officers to observe statutes such as this established by state action in furtherance of the public health and welfare, and otherwise so conduct their affairs as to promote public confidence and good will.
While it is Congress that is given the power to regulate commerce among the States, some state regulation of that commerce is permissible. “When Congress has not exerted its power under the Commerce Clause, and state regulation of matters of local concern is so related to interstate commerce that it also operates as a regulation of that commerce, the reconciliation of the power thus granted with that reserved to the state is to be attained by the accommodation of the competing demands of the state and national interests involved.” Parker v. Brown, 317 U. S. 341, 361-363. State regulation is to be upheld if “upon a consideration of all the relevant facts and circumstances it appears that the matter is one which may appropriately be regulated in the interest of the safety, health and well-being of local communities, and which, because of its local character and the practical difficulties involved, may never be adequately dealt with by Congress.” Ibid., p. 362.
The common sense view has been taken that even though Congress has not legislated to that effect, local law existing at the time an enclave is acquired, which does not defeat the national purpose, remains in effect within the enclave until altered by Congress. Stewart & Co. v. Sadrakuta, 309 U. S. 94. And the States may qualify their consent to the federal government’s purchase by retaining some measure of jurisdiction. James v. Dravo Contracting Co., 302 U. S. 134.