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.
In 1995, the Court in United States v. Lopez 1 Footnote
514 U.S. 549 (1995) . struck down a federal statute prohibiting possession of a gun at or near a school, rejecting an argument that possession of firearms in school zones can be punished under the Commerce Clause because of its economic effects.2 Footnote
Id. at 564–65 . Accepting that rationale, the Court said, would eliminate the “distinction between what is truly national and what is truly local,” would convert Congress’s commerce power into a general police power of the sort retained by the States, and would undermine the first principle that the federal government is one of enumerated and limited powers.3 Footnote
Id. at 552, 567–68 .
Application of the same principle led five years later to the Court’s decision in United States v. Morrison 4 Footnote
529 U.S. 598 (2000) . invalidating a provision of the Violence Against Women Act (VAWA) that created a federal cause of action for victims of gender-motivated violence. The Court concluded that Congress may not regulate “noneconomic, violent criminal conduct based solely on that conduct’s aggregate effect on interstate commerce.” 5 Footnote
Id. at 617 . “[W]e can think of no better example of the police power, which the Founders denied the National Government and reposed in the States, than the suppression of violent crime and vindication of its victims.” 6 Footnote
Id. at 618 .
In contrast to Lopez and Morrison , the Court in Gonzales v. Raich upheld Congress’s authority under the Commerce Clause to prohibit the intrastate cultivation and use of medical marijuana, based on its aggregate effect on interstate commerce.7 Footnote
545 U.S. 1, 22 (2005) . Raich distinguished Lopez and Morrison as regulations of noneconomic activity,8 Footnote
Id. at 25 . relying mainly on older Commerce Clause precedents.9 Footnote
Id. at 17–21 (discussing Wickard v. Filburn, 317 U.S. 111 (1942) ). The majority in Raich referenced the Tenth Amendment only obliquely through a cite to United States v. Darby ,10 Footnote
Id. at 29 ( “[S]tate action cannot circumscribe Congress’ plenary commerce power.” (citing United States v. Darby, 312 U.S. 100, 114 (1941) )). while the dissenters did so more directly, arguing this application of federal law unconstitutionally encroached on state police powers.11 Footnote
Id. at 50 (O’Connor, J., dissenting) ( “It will not do to say that Congress may regulate noncommercial activity simply because it may have an effect on the demand for commercial goods . . . . We have already rejected the result that would follow—a federal police power.” (citing Lopez , 514 U.S. at 564 )); id. at 66 (Thomas, J., dissenting) ( “Here, Congress has encroached on States’ traditional police powers to define the criminal law and to protect the health, safety, and welfare of their citizens.” ).
In the 2012 case National Federation of Independent Business v. Sebelius , the Court held that Congress’s Commerce Clause power could not be used to compel individuals to engage in commercial activity.12 Footnote
Nat’l Fed’n of Indep. Bus. v. Sebelius, 567 U.S. 519, 552 (2012) (plurality opinion of Roberts, C.J.). As a result, the “individual mandate” of the Patient Protection and Affordable Care Act, which required most uninsured individuals to buy health insurance or pay a penalty,13 Footnote
Id. at 539 . was beyond Congress’s Commerce Clause power.14 Footnote
Id. at 558 . The Court ultimately upheld the individual mandate under Congress’s taxing power. Id. at 561–63 . On route to this holding, the Court noted that Congress’s enumerated powers “must be read carefully to avoid creating a general federal authority akin to the police power,” invoking the Tenth Amendment and related federalism principles.15 Footnote
Id. at 535–36 .
Footnotes 1 514 U.S. 549 (1995) . 
2 Id. at 564–65 . 3 Id. at 552, 567–68 . 4 529 U.S. 598 (2000) . 5 Id. at 617 . 6 Id. at 618 . 7 545 U.S. 1, 22 (2005) . 8 Id. at 25 . 9 Id. at 17–21 (discussing Wickard v. Filburn, 317 U.S. 111 (1942) ). 10 Id. at 29 ( “[S]tate action cannot circumscribe Congress’ plenary commerce power.” (citing United States v. Darby, 312 U.S. 100, 114 (1941) )). 11 Id. at 50 (O’Connor, J., dissenting) ( “It will not do to say that Congress may regulate noncommercial activity simply because it may have an effect on the demand for commercial goods . . . . We have already rejected the result that would follow—a federal police power.” (citing Lopez , 514 U.S. at 564 )); id. at 66 (Thomas, J., dissenting) ( “Here, Congress has encroached on States’ traditional police powers to define the criminal law and to protect the health, safety, and welfare of their citizens.” ). 12 Nat’l Fed’n of Indep. Bus. v. Sebelius, 567 U.S. 519, 552 (2012) (plurality opinion of Roberts, C.J.). 13 Id. at 539 . 14 Id. at 558 . The Court ultimately upheld the individual mandate under Congress’s taxing power. Id. at 561–63 . 15 Id. at 535–36 .
