States' rights refers to the iea, in U.S. politics and constitutional law, that U.S. states possess certain rights and political powers in relation to the federal government. A commonly cited source for states' rights is the Tenth Amendment to the Constitution, which is part of the Bill of Rights. The states' rights concept is usually used to defend a state law that the federal government seeks to override, or to oppose a perceived violation by the federal government of the bounds of federal authority.