134 McCONNELL v. FEDERAL ELECTION COMM'N Opinion of the Court national to state party committees by prohibiting state and local party committees from using such funds for activities that affect federal elections. 2 U. S. C. §441i(b). These "Federal election activit[ies]," defined in new FECA §301(20)(A), are almost identical to the mixed-purpose activities that have long been regulated under the FEC's preBCRA allocation regime. 2 U.S.C. §431(20)(A). New FECA §323(d) reinforces these soft-money restrictions by prohibiting political parties from soliciting and donating funds to tax-exempt organizations that engage in electioneering activities. 2 U.S.C. §441i(d). New FECA §323(e) restricts federal candidates and officeholders from receiving, spending, or soliciting soft money in connection with federal elections and limits their ability to do so in connection with state and local elections. 2 U. S. C. §441i(e). Finally, new FECA § 323(f) prevents circumvention of the restrictions on national, state, and local party committees by prohibiting state and local candidates from raising and spending soft money to fund advertisements and other public communications that promote or attack federal candidates. 2 U. S. C. §441i(f). Plaintiffs mount a facial First Amendment challenge to new FECA § 323, as well as challenges based on the Elections Clause, U. S. Const., Art. I, §4, principles of federalism, and the equal protection component of the Due Process Clause. We address these challenges in turn. A In Buckley and subsequent cases, we have subjected restrictions on campaign expenditures to closer scrutiny than limits on campaign contributions. See, e. g., Federal Election Comm'n v. Beaumont, 539 U. S.146, 161 (2003); see also Nixon v. Shrink Missouri Government PAC, 528 U. S.377, 387-388 (2000); Buckley, 424 U. S., at 19. In these cases we have recognized that contribution limits, unlike limits on expenditures, "entai[l] only a marginal restriction upon the