8 MCCUTCHEON v. FEDERAL ELECTION COMM’N Opinion of ROBERTS, C. J. Government may regulate protected speech only if such regulation promotes a compelling interest and is the least restrictive means to further the articulated interest. See Sable Communications of Cal., Inc. v. FCC, 492 U. S. 115, 126 (1989). By contrast, the Court concluded that contribution limits impose a lesser restraint on political speech because they “permit[ ] the symbolic expression of support evidenced by a contribution but do[ ] not in any way infringe the contributor’s freedom to discuss candidates and issues.” Buckley, 424 U. S., at 21. As a result, the Court focused on the effect of the contribution limits on the freedom of political association and applied a lesser but still “rigorous standard of review.” Id., at 29. Under that standard, “[e]ven a ‘ “significant interference” with protected rights of political association’ may be sustained if the State demonstrates a sufficiently important interest and employs means closely drawn to avoid unnecessary abridgement of associational freedoms.” Id., at 25 (quoting Cousins v. Wigoda, 419 U. S. 477, 488 (1975)). The primary purpose of FECA was to limit quid pro quo corruption and its appearance; that purpose satisfied the requirement of a “sufficiently important” governmental interest. 424 U. S., at 26–27. As for the “closely drawn” component, Buckley concluded that the $1,000 base limit “focuses precisely on the problem of large campaign contributions . . . while leaving persons free to engage in independent political expression, to associate actively through volunteering their services, and to assist to a limited but nonetheless substantial extent in supporting candidates and committees with financial resources.” Id., at 28. The Court therefore upheld the $1,000 base limit under the “closely drawn” test. Id., at 29. The Court next separately considered an overbreadth challenge to the base limit. See id., at 29–30. The challengers argued that the base limit was fatally overbroad