State antitrust laws are broadly constructed. With sweeping, general terms, often mirroring the language of the federal anti- trust laws, most state antitrust statutes manifest a legislative design to prevent-and to punish a variety of commercial activities that are anticompetitive in purpose or effect. These statutes, in conjunction with consumer protection statutes, constitute the primary vehicles through which state authorities protect consumers from harmful, anticompetitive behavior. Of course, despite the importance of state antitrust laws in preserving a competitive marketplace, the Constitution confines their reach. Through the Commerce Clause, the Constitution vests in Congress the exclusive power to regulate interstate commerce. Accordingly, since passage of the Sherman Act in 1890, Congress has promulgated an extensive body of antitrust legislation regulating interstate commercial conduct. Another federal constraint on state antitrust laws arises through the Supremacy Clause. To the extent that state antitrust laws conflict with federal legislation in the same field, courts will find them constitutionally invalid.
State antitrust statutes, however, are not completely preempted by federal antitrust laws. Instead, the legislative history accompanying most state and federal antitrust statutes indicates that the two sets of statutes were designed to function as equally potent ingredients in a comprehensive protective scheme. In fact, early federal antitrust legislation directly reflected the policies behind the state antitrust laws of the late nineteenth century; they also reflected contemporary principles of common law. As coexisting and complementary instruments, state and federal antitrust statutes form an excellent example of the potential for effective multi-layered legislation. In one court's analysis, the relationship between the federal and state antitrust laws is a quintessential ex- ample of "cooperative federalism."'
David W. Lamb,
Avoiding Impotence: Rethinking the Standards for Applying State Antitrust Laws to Interstate Commerce,
54 Vanderbilt Law Review
Available at: https://scholarship.law.vanderbilt.edu/vlr/vol54/iss4/5