Bill of Federalism
Proposed by Randy Barnett, the Bill of Federalism is an American conservative initiative, for amendment(s) to the U.S. Constitution to "to restore the balance between state and federal power as well as the original meaning of the Constitution". Barnett is a professor of constitutional law at Georgetown University, who has argued before the Supreme Court of the United States, so cannot be immediately dismissed as a wild-eyed extremist.  By no means is it accepted by all conservatives. Some object because it does not go far enough, but others do not agree with the particular theories of constitutional law that it assumes.
It has, however, been taken up as a rallying point by a number of Tea Party movement activists, possibly more concerned with the tactics of limiting the Federal government than of legal nuance.