The article is a paper presented during the Poland-wide academic conference The U.S. Constitution – theory and practice. The basis for reflections constitutes an issue of the constitutionality of the federal legislation establishing restrictions on the money’s influence on financing election campaigns. The paper focuses on an analysis of the U.S. Supreme Court’s case law related to the range of an acceptable interference of such regulations in the freedom of speech and political expression clause of the First Amendment to the Constitution. The author discusses selected statements contained in the rulings made in cases, from which as the most crucial he regards: Buckley v. Valeo (1976), McConnell v. Federal Election Commission (2003) and Citizens United v. Federal Election Commission (2010). In the conclusion of the article an opinion is presented that the U.S. Supreme Court judicature, co-creating with the federal legislation the campaign finance law, is an unique attempt at balancing the two values fundamental to the democratic election process, which are freedom of speech and the principle of equal opportunities for political competitors.