USA state governments are semi-sovereign. Education standards, driving regulations, murder prosecutions, etc. are all done by the state government. Interstate c

USA state governments are semi-sovereign. Education standards, driving regulations, murder prosecutions, etc. are all done by the state government. Interstate commerce or foreign relations has to be involved for the federal government to handle it. Municipal corporations derive their authority from the state government and in theory can be dissolved at any time. So when they ban cities from raising the minimum wage but complain about a federal mandate they are legally correct.