The Court came to its multifaceted decision on January 30, 1976, which left FECA in a very different state than when it was first passed. The first part of the opinion in Buckley ruled that the FECA provision imposing limitations on individual campaign contributions is constitutional. The Court also found the recordkeeping and reporting requirements of the Act constitutional. However, the Court found the limitations on campaign expenditures unconstitutional as an abridgment of candidates' First Amendment free speech rights.
The multi-part decision begins with the Court upholding the restrictions in FECA on individual contributions to political campaigns in order to protect to integrity of the electoral process. The Court found that restrictions on individual contributions "necessarily reduce[d] the quantity of expression by restricting the number of issues discussed, the depth of the exploration, and the size of the audience reached." In essence, the Court saw expenditure of money as the crux of modern free speech rights, and thus, such a restriction would require a governmental interest in doing so. The Court found such a justification, stating that election laws are the "primary weapons against the reality or appearance of improper influence stemming from the dependence of candidates on large campaign contributions." Thus, though the law did restrict speech rights to some degree, it did not impinge upon the fundamental speech rights through its protection of the electoral process from corruption by wealthy contributors in the eyes of the Court.
The appellants in Buckley sought to exempt all reporting requirements regarding the nature and source of campaign contributions made during federal elections. The Court, however, upheld these requirements, stating that there were significant governmental interests that compelled such disclosures. Among these interests, the Court cited the deterrence of corruption, allowance of voters to fully evaluate candidates and a means to detect election law violations. The Court did note that disclosure presented some threat to minor parties who may face threats or public reprisal for their contribution, though none were present in this case. Thus, the Court left open the possibility of minor parties bringing a challenge against FECA in the future if an injury-in-fact could be shown.
Another key component of the decision was the Court's finding that governmental restriction of independent expenditures during campaigns, limits on candidates' personal expenditures for campaigns and limits on total campaign expenditures all violate First Amendment speech rights. These practices, the Court found, do not raise the potential for corruption in the same way individual contributions might, and the "direct and substantial restraints on the quantity of political speech" were not based upon a high degree of danger posed by these activities. Thus, because this danger is not significantly high, the Court refused to curtail free speech and association rights for the marginal protections the restrictions could afford. The appellees in the case argued that these restrictions would even the electoral field by limiting the amount every campaign could spend. The Court, however, saw that it would be important that money spent on campaigns would vary with the "size and intensity" of support for a particular candidate. In the Court's opinion, for the judiciary to make decisions about the wasteful or excessive nature of campaign spending would be an unconstitutional use of its power. Similarly, the Court viewed a restriction on a candidate's use of personal funds as an unconstitutional interference with an individual's right to engage in discussion of public issues and advocate for his or her own election.
Another procedural challenge in this case was based upon the method of appointing the six members of the FEC. The procedure mandated in FECA provided that the president, the Speaker of the House of Representatives and the President pro tempore of the Senate would each appoint two members at their discretion. The Court found that the Appointments Clause of the Constitution permitted only the president to appoint officers, with the advice of the Senate. The Court went further, stating that the Commission, as it was configured, could not exert executive functions because it was legislative in nature, failing to satisfy Appointments Clause restrictions limiting its members to those appointed solely by the president. The Court allowed all past decisions of the FEC to stand and required that the appointment provision be rewritten in compliance with the Appointments Clause.