Although the Constitution grants broad powers to Congress, our federalism requires that Congress treat the States in a manner consistent with their status as residuary sovereigns and joint participants in the governance of the Nation. See, e.g., United States v. Lopez, 514 U.S., at 583, 115 S.Ct. 1624 (KENNEDY, J., concurring); Printz, 521 U.S., at 935, 117 S.Ct. 2365; New York, 505 U.S., at 188, 112 S.Ct. 2408. The founding generation thought it “neither becoming nor convenient that the several States of the Union, invested with that large residuum of sovereignty which had not been delegated to the United States, should be summoned as defendants to answer the complaints of private persons.” In re Ayers, 123 U.S., at 505, 8 S.Ct. 164.