Federalism is a chameleon-like concept whose appearance changes with the academic terrain. The concept clearly has something to do with the allocation of power between national and local governmental entities, but how this allocation is interpreted depends upon profession and discipline. Economists, for example, view federalism as an invitation to specify the most efficient possible arrangement of national and local power, whereas political scientists view federalism as a matter of generating descriptive and perhaps predictive models of these arrangements. For American constitutional lawyers and judges, however, federalism means something altogether different; it entails the articulation of constitutional values that specify how power ought...