"This essay offers a new defense of judicial review of the Constitution's federal structure. It begins by showing that federalism is best understood not as a system that creates rights for states but one that provides benefits for the citizens of the nation. It achieves this goal by distributing powers best exercised at the national level to the federal government and those best exercised more locally to the states. The benefits of this distribution include catering to diverse preferences of citizens in different states and creating horizontal competition among the states for efficient provision of government services. "
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=578143
{Linked from instapudit}