Holdings have made clear that the relevant question is not simply whether a private group is serving a 'public function' but whether the function performed has been 'traditionally the exclusive prerogative of the State.' Jackson, 419 U. S. 353; quoted in Blum v. Yaretsky, 457 U. S. 1011 (emphasis added).
Under the Court’s cases, a private entity may qualify as a state actor when it exercises “powers traditionally exclusively reserved to the State.” Jackson, 419 U. S., at 352, 95 S. Ct. 449, 42 L. Ed. 2d 477. It is not enough that the federal, state, or local government exercised the function in the past, or still does. And it is not enough that the function serves the public good or the public interest in some way. Rather, to qualify as a traditional, exclusive public function within the meaning of our state-action precedents, the government must have traditionally and exclusively performed the function. See Rendell-Baker v. Kohn, 457 U. S. 830, 842, 102 S. Ct. 2764, 73 L. Ed. 2d 418 (1982); Jackson, 419 U. S., at 352-353, 95 S. Ct. 449, 42 L. Ed. 2d 477; Evans v. Newton, 382 U. ...