In upholding the constitutional validity of the Act's contribution and expenditure provisions on the ground [424 U.S. 1, 16] that those provisions should be viewed as regulating conduct, not speech, the Court of Appeals relied upon United States v. O'Brien, 391 U.S. 367 (1968). See 171 U.S. App. D.C., at 191, 519 F.2d, at 840. The O'Brien case involved a defendant's claim that the First Amendment prohibited his prosecution for burning his draft card because his act was "`symbolic speech'" engaged in as a "`demonstration against the war and against the draft.'" 391 U.S., at 376 . On the assumption that "the alleged communicative element in O'Brien's conduct [was] sufficient to bring into play the First Amendment," the Court sustained the conviction because it found "a sufficiently important governmental interest in regulating the non-speech element" that was "unrelated to the suppression of free expression" and that had an "incidental restriction on alleged First Amendment freedoms . . . no greater than [was] essential to the furtherance of that interest." Id., at 376-377. The Court expressly emphasized that O'Brien was not a case "where the alleged governmental interest in regulating conduct arises in some measure because the communication allegedly integral to the conduct is itself thought to be harmful." Id., at 382.
We cannot share the view that the present Act's contribution and expenditure limitations are comparable to the restrictions on conduct upheld in O'Brien. The expenditure of money simply cannot be equated with such conduct as destruction of a draft card. Some forms of communication made possible by the giving and spending of money involve speech alone, some involve conduct primarily, and some involve a combination of the two. Yet this Court has never suggested that the dependence of a communication on the expenditure of money operates itself to introduce a non speech element or to reduce the exacting scrutiny required by the First Amendment. See Bigelow v. Virginia, 421 U.S. 809 , [424 U.S. 1, 17] 820 (1975); New York Times Co. v. Sullivan, supra, at 266. For example, in Cox v. Louisiana, 379 U.S. 559 (1965), the Court contrasted picketing and parading with a newspaper comment and a telegram by a citizen to a public official. The parading and picketing activities were said to constitute conduct "intertwined with expression and association," whereas the newspaper comment and the telegram were described as a "pure form of expression" involving "free speech alone" rather than "expression mixed with particular conduct." Id., at 563-564.
Even if the categorization of the expenditure of money as conduct were accepted, the limitations challenged here would not meet the O'Brien test because the governmental interests advanced in support of the Act involve "suppressing communication." The interests served by the Act include restricting the voices of people and interest groups who have money to spend and reducing the overall scope of federal election campaigns. Although the Act does not focus on the ideas expressed by persons or groups subject to its regulations, it is aimed in part at equalizing the relative ability of all voters to affect electoral outcomes by placing a ceiling on expenditures for political expression by citizens and groups. Unlike O'Brien, where the Selective Service System's administrative interest in the preservation of draft cards was wholly unrelated to their use as a means of communication, it is beyond dispute that the interest in regulating the alleged "conduct" of giving or spending money "arises in some measure because the communication allegedly integral to the conduct is itself thought to be harmful." 391 U.S., at 382 .
Nor can the Act's contribution and expenditure limitations be sustained, as some of the parties suggest, by reference to the constitutional principles reflected in such [424 U.S. 1, 18] decisions as Cox v. Louisiana, supra; Adderley v. Florida, 385 U.S. 39 (1966); and Kovacs v. Cooper, 336 U.S. 77 (1949). Those cases stand for the proposition that the government may adopt reasonable time, place, and manner regulations, which do not discriminate among speakers or ideas, in order to further an important governmental interest unrelated to the restriction of communication. See Erznoznik v. City of Jacksonville, 422 U.S. 205, 209 (1975). In contrast to O'Brien, where the method of expression was held to be subject to prohibition, Cox, Adderley, and Kovacs involved place or manner restrictions on legitimate modes of expression - picketing, parading, demonstrating, and using a soundtruck. The critical difference between this case and those time, place, and manner cases is that the present Act's contribution and expenditure limitations impose direct quantity restrictions on political communication and association by persons, groups, candidates, and political parties in addition to any reasonable time, place, and manner regulations otherwise imposed. 17 [424 U.S. 1, 19]
A restriction on the amount of money a person or group can spend on political communication during a campaign necessarily reduces the quantity of expression by restricting the number of issues discussed, the depth of their exploration, and the size of the audience reached. This is because virtually every means of communicating ideas in today's mass society requires the expenditure of money. The distribution of the humblest handbill or leaflet entails printing, paper, and circulation costs. Speeches and rallies generally necessitate hiring a hall and publicizing the event. The electorate's increasing dependence on television, radio, and other mass media for news and information has made these expensive modes of communication indispensable instruments of effective political speech.
The expenditure limitations contained in the Act represent substantial rather than merely theoretical restraints on the quantity and diversity of political speech. The $1,000 ceiling on spending "relative to a clearly identified candidate," 18 U.S.C. 608 (e) (1) (1970 ed., Supp. IV), would appear to exclude all citizens and groups except candidates, political parties, and the institutional press from any significant use of the most [424 U.S. 1, 20] effective modes of communication. Although the Act's limitations on expenditures by campaign organizations and political parties provide substantially greater room for discussion and debate, they would have required restrictions in the scope of a number of past congressional and Presidential campaigns and would operate to constrain campaigning by candidates who raise sums in excess of the spending ceiling.
By contrast with a limitation upon expenditures for political expression, a limitation upon the amount that any one person or group may contribute to a candidate or political committee entails only a marginal restriction upon the contributor's ability to engage in free communication. [424 U.S. 1, 21] A contribution serves as a general expression of support for the candidate and his views, but does not communicate the underlying basis for the support. The quantity of communication by the contributor does not increase perceptibly with the size of his contribution, since the expression rests solely on the undifferentiated, symbolic act of contributing. At most, the size of the contribution provides a very rough index of the intensity of the contributor's support for the candidate. A limitation on the amount of money a person may give to a candidate or campaign organization thus involves little direct restraint on his political communication, for it permits the symbolic expression of support evidenced by a contribution but does not in any way infringe the contributor's freedom to discuss candidates and issues. While contributions may result in political expression if spent by a candidate or an association to present views to the voters, the transformation of contributions into political debate involves speech by someone other than the contributor.
