THE current consensus among savants of American federalism is that, at long last, power is shifting back to the states. The Cold War, which gave Washington politicians a national-security pretext for immersing themselves in local tasks like building bridges and highways, is history. Republican majorities, reputedly solicitous of state sovereignty, have controlled Congress since 1995. They promptly enacted legislation that would supposedly kick the congressional habit of heaping expensive obligations on state and local governments but not appropriating the money to help them comply. A year later, Congress also put the states in charge of handling more of the national welfare program. The Clinton administration not only signed off on this devolution but granted state agencies a degree of discretion in administering Medicaid and in managing some aspects of U.S. environnaental policy. Much of the energy stirring public policy these days—from school reform to the reprise of prohibitionism (this time targeting tobacco)--seems to emanate from the statehouses. Perhaps most notably, during the past few years the Supreme Court has handed down several opinions that have sought to shore up prerogatives of the states. (Soon there may be a few more of these opinions: In the coming year, the Court will decide whether states can be sued in federal court for alleged job discrimination against persons with disabilities and whether the Army Corps of Engineers can prevent a state from building a landfill that might upset the habitats of some migratory birds.)