Federalism is sometimes said to be an unstable halfway house between unified national government and an alliance among separate the state, according to which sovereignty must ultimately be indivisible: either national institutions retain the authority to make decisions or they do not. Genuine federal arrangements are unstable under this perspective. The notion of indivisible sovereignty has a powerful hold on our view of politics, but we think it is limited, most importantly by its conflation of the question of where ultimate authority resides with the question of where state power is actually exerted. While the answer to the first question is obviously significant, economic and sociological conceptions of politics suggest that the answer to the second may tell much more about the nature of a polity.
Perhaps the main attraction of federalism in a country riven by internal differences is that it permits foundational issues like the location of sovereignty to be finessed, so that internal divisions can be accommodated in ad hoc, practical ways. It permits people who may differ greatly in their conception of a good public life to develop and maintain their own separate communities within the context of a larger and more powerful political economy, without requiring them to surrender their separate identities.' Echoing Rawls, we view federalism as a political rather than a metaphysical solution to the formation and maintenance of a state.
William N. Eskridge, Jr. and John Ferejohn,
The Elastic Commerce Clause: A Political Theory of American Federalism,
47 Vanderbilt Law Review
Available at: https://scholarship.law.vanderbilt.edu/vlr/vol47/iss5/5