You can find the U.S. Supreme Court’s opinion in Printz v. United States online using just about any search engine, for example, Google Scholar. (Make sure you click on Legal Documents if you want cases.)
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Printz v. U.S.
U.S. Supreme Court (95-1478)
521 U.S. 898
Argued December 3, 1996
Decided June 27, 1997
“…. Today we hold that Congress cannot circumvent that prohibition by conscripting the States’ officers directly. The Federal Government may neither issue directives requiring the States to address particular problems, nor command the States’ officers, or those of their political subdivisions, to administer or enforce a federal regulatory program. It matters not whether policymaking 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. Accordingly, the judgment of the Court of Appeals for the Ninth Circuit is reversed….”