Chief Justice William H. Rehnquist and the Supreme Court under his leadership have been charged, respectively, with leading and enacting a federalism revolution. From the beginning, Rehnquist, first as an associate justice and later as Chief Justice, has displayed a commitment to notions of constitutionalism, originalism, and federalism. In the years before Rehnquist joined the Supreme Court, the idea of federalism, what Felix Frankfurter described as the happy relation of States to Nation, certainly underwent numerous transformations, altering it from what was originally intended into a doctrine far friendlier to the expansion of national power at the expense of the States. It is essential to understand these changes and their broad...