The Establishment Clause provides that Congress shall make no law respecting an establishment of religion. Amdt. 1. As a textual matter, this Clause probably prohibits Congress from establishing a national religion. But see P. Hamburger, Separation of Church and State 106, n. 40 (2002) (citing sources). Perhaps more importantly, the Clause made clear that Congress could not interfere with state establishments, notwithstanding any argument that could be made based on Congress power under the Necessary and Proper Clause. See A. Amar, The Bill of Rights 36?39 (1998).
Nothing in the text of the Clause suggests that it reaches any further. The Establishment Clause does not purport to protect individual rights. By contrast, the Free Exercise Clause plainly protects individuals against congressional interference with the right to exercise their religion, and the remaining Clauses within the First Amendment expressly disable Congress from abridging [particular] freedom. (Emphasis added.) This textual analysis is consistent with the prevailing view that the Constitution left religion to the States. See, e.g., 2 J. Story, Commentaries on the Constitution of the United States §1873 (5th ed. 1891); see also Amar, The Bill of Rights, at 32?42; id., at 246?257. History also supports this understanding: At the founding, at least six States had established religions, see McConnell, The Origins and Historical Understanding of Free Exercise of Religion, 103 Harv. L. Rev. 1409, 1437 (1990). Nor has this federalism point escaped the notice of Members of this Court. See, e.g., Zelman, supra, at 677?680 (THOMAS, J., concurring); Lee, supra, at 641 (SCALIA, J., dissenting).
Quite simply, the Establishment Clause is best understood as a federalism provision - it protects state establishments from federal interference but does not protect any individual right.