The past several years have witnessed a five Justice majority of the Supreme Court enunciating increasingly severe limitations upon Congress’ Article I powers. One effort by these five Justices has emanated from a unique explication of the Eleventh Amendment which began with Seminole Tribe v. Florida in 1996 and was expanded by three decisions announced on June 23, 1999. This Quartet of decisions has significantly limited congressional power. This doctrine, the author contends, represents a revival of the Calhounian nullification doctrine which was a primary intellectual underpinning of southern secession in the last century. [Justice Souter asserts that it is a revival of “industrial due process.”] The article examines the doctrine as explicated by Seminole Tribe and its progeny as it establishes severe limits on Congressional power, enunciates an undefined doctrine of concurrent sovereignty between the states and the federal government, declares that the use of property is not within the ambit of the Due Process Clause of the Fourteenth Amendment, and reallocates the demarcation of the separation of powers by declaring that federal courts will not only ask what Congress did, but also why Congress did it, and whether Congress had sufficient evidentiary support to do it. The article surveys the impact this Quartet of decisions may have upon environmental law by examining the impact upon the jurisdictional reach of the Clean Water Act, whether a state may be held liable as a potentially responsible party under CERCLA by a private party, whether there is a new basis to challenge the National Ambient Air Quality Standards of the Clean Air Act, the implications for takings litigation, and the potential impact upon delegated authority and citizen suits. With the advent of the Calhounian Quartet, the article concludes, one is sailing upon uncharted seas without a compass, much less a global positioning system.