Conflict between the enumerated powers of Congress and the reserved powers of the states began early and continued long. The Constitution gives to the legislative branch primacy over broad areas, including taxation and the regulation of interstate and foreign commerce, plus all powers "necessary and proper" for putting its specified authority into effect. But such qualified authority is occasionally clouded by the first ten amendments, which limit the role of the central government. Ratified in 1791 as part of the Bill of Rights, the Tenth Amendment declares that all powers not delegated by the Constitution to the federal government nor denied to the states are reserved to the states respectively or the people. Adding cushion is the Eleventh Amendment that grants states freedom from being unwillingly hauled into federal court by citizens having nonconstitutional complaints.

In this chapter we examine how the new judicial activism of the Supreme Court underscores the fluidity of states' rights (i.e., the prerogative power of a state to exercise its inherent authority as opposed to rights of the federal government), or "state rights," the prevalent usage proceeding the Civil War, in the congressional arena. For much of our nation's history states' rights were either the claimants of the party out of power (Current 1995) or almost exclusively equated with resistance to increasing civil rights protection, opposition to social legislation on a national level, and conservative economic benefits (Drake and Nelson 1999). Contemporary federal-state relations, however, are emerging in different ways. Central to the revitalized rights of states is the Supreme Court's new activism, which is defining new, unexpected rights for states (Stack and Campbell 2001). In a series of landmark decisions, reinvigorating the Tenth Amendment and substantially defining the Eleventh Amendment, a bare majority of justices are redefining traditional federal-state relations, moving toward a dual federalist approach long abandoned since the late 1930s. The Supreme Court is also redefining long-established rights created under the Fourteenth Amendment's equal protection clause. This trend reflects historical periods when beliefs developed that states would better solve pressing matters as well as protect more effectively the rights of individuals.