Federalism, State Sovereignty and the Constitution: Basis and Limits of Congressional Power [Updated February 1, 2008] [open pdf - 177KB]
"The lines of authority between states and the federal government are, to a significant extent, defined by the United States Constitution and relevant case law. In recent years, however, the Supreme Court has decided a number of cases that would seem to reevaluate this historical relationship. This report discusses state and federal legislative power generally, focusing on a number of these 'federalism' cases. The report does not, however, address the much larger policy issue of when it is appropriate-as opposed to constitutionally permissible-for federal powers to be exercised."
CRS Report for Congress, RL30315