What important values are furthered by a system founded on the doctrine of states' Rights?

Hey guys. You answer my question well- I'll answer yours well. Basically, the federal system created by the Constitution has produced much debate historically about the proper roles of the federal and state governments. I need to explain the doctrine of states’ rights and make an argument for its adoption. What important values are furthered by a system founded on the doctrine of states’ rights? What problems, if any, do you see in a government system based on the doctrine of states’ rights?