"In American political discourse, states' rights refers to political powers reserved for the state governments rather than the federal government according to the United States Constitution, reflecting especially the enumerated powers of Congress and the Tenth Amendment. The enumerated powers that are listed in the Constitution include exclusive federal powers, as well as concurrent powers that are shared with the states, and all of those powers are contrasted with the reserved powers—also called states' rights—that only the states possess" wiki on states' rights
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people. " 10th Amendment to the US Constitution
The states of the South have always been devoted to the notion of federalism and the rights of the states. The rest of the country? not so much ... IMO the South has favored federalism because it has always been weaker party in a division of the country into cultural zones,
Now we have an emerging situation in which anti-Trump and liberal states in the Deep North and West are using the mantle of states rights to oppose the power of the federal government.
The governor of Washington looked mighty funny gloating on TV over Washington State's victory over the federal government, mighty funny. pl