Enhancing GovernmentFederalismthe division of power between national and state governmentshas been a divisive issue throughout American history. Conservatives argued in support of federalism and states' rights to oppose the end of slavery, the New Deal, and desegregation. In the 1990s, the Rehnquist Court used federalism to strike down numerous laws of public good, including federal statutes requiring the clean up of nuclear waste and background checks for gun ownership.