...where the practicalities of federalism — or, more precisely, the underlying assumptions of our dull form of government and the consequent presuppositions...across what might otherwise be the implied range of the legislation. Congress may choose, as it has chosen frequently in the past, to regulate only part...

...nondiscrimi" See Frankfurter, Some Reflections on the Reading of Statutes, 47 Colum. L. Rev. 527, 540 (1947) ("The underlying assumptions of our dual form of government,...might otherwise be the implied range of legislation"). »Cf. Heublein, Inc. v. South Carolina Tax Comm'n, 409 US 275, 281-282 (1972) ("'[Ulnless Congress...

...functions of the individual states. Federal legislation of this character cannot therefore be constructed without regard to the implications of our dual system...Government takes over such local radiations in the vast network of our national economic enterprise and thereby radically readjusts the balance of state...

...functions of the individual states. Federal legislation of this character cannot therefore be constructed without regard to the implications of our dual system....justifies] the generalization that, when the Federal Gcvernaer.t takes over such local radiations in the vast network of our national economic enterprise...

...unitary government. It cannot be accepted where the practicalities of federalism—or, more precisely, the underlying assumptions of our dual form of government...across what might otherwise be the implied range of the legislation. Congress may choose, as it has chosen frequently in the past, to regulate only part...