“We held in New York that Congress cannot compel the States to enact or enforce a federal regulatory program. Today we hold that Congress cannot circumvent that prohibition by conscripting the State’s officers directly. The Federal Government may neither issue directives requiring the States to address particular problems, nor command the State’s officers or those of their political subdivisions, to administer or enforce a federal regulatory program. It matters not whether policy making is involved, and no case-by-case weighing of the burdens or benefits is necessary; such commands are fundamentally incompatible with our constitutional system of dual sovereignty.”

and,

“The Federal Government may not compel the States to implement, by legislation or executive action, federal regulatory programs. We warned that this Court never has sanctioned explicitly a federal command to the States to promulgate and enforce laws and regulations, ‘The Federal Government,’ we held, ‘may not compel the States to enact or administer a federal regulatory program.’” – Printz v. U.S. (95-1478, 1997)