Few Supreme Court decisions in recent memory have shaped American campaign finance as profoundly as Citizens United v. Federal Election Commission, decided on January 21, 2010. The ruling reshaped the rules governing how corporations, unions, and other organizations can spend money in elections, and it became a focal point for a long running debate about whether corporations should enjoy the same speech rights as individual citizens. Understanding the case requires looking at the dispute that produced it, the legal reasoning behind the decision, the precedents it overturned, and the questions it left unresolved.
The case began with a film. In 2008, a conservative nonprofit organization called Citizens United produced a documentary critical of Hillary Clinton, who was then a candidate for the Democratic presidential nomination. The group wanted to distribute the film through video on demand and to advertise it during the primary season. The problem was that the Bipartisan Campaign Reform Act of 2002, often called the McCain Feingold law after its principal sponsors, restricted what it termed electioneering communications. These were broadcast advertisements that named a federal candidate and aired close to an election, and the law barred corporations and unions from paying for them out of their general treasuries.
Because Citizens United was a corporation, even though it was a nonprofit advocacy group, federal regulators treated its film and advertisements as covered by these restrictions. Citizens United challenged the law, arguing that applying these limits to its film violated the First Amendment guarantee of free speech. The dispute traveled to the Supreme Court, which used it to address a much broader question than the narrow facts of one documentary.
By a vote of five to four, the Supreme Court held that the government may not prohibit corporations and unions from making independent expenditures for political speech. Writing for the majority, Justice Anthony Kennedy reasoned that political speech does not lose its First Amendment protection simply because the speaker is a corporation rather than an individual. In the majority's view, the First Amendment protects the speech itself, and the identity of the speaker, whether a person, a group, a union, or a corporation, does not justify banning that speech.
The majority emphasized that the spending at issue was independent, meaning it was not coordinated with any candidate or campaign. Drawing on the earlier reasoning of Buckley v. Valeo in 1976, the Court held that independent spending does not give rise to the kind of corruption that justifies restricting direct contributions. If independent expenditures by individuals are protected, the majority concluded, there was no principled basis for treating independent expenditures by corporations and unions differently.
The four dissenting justices strongly disagreed. In a long dissent, Justice John Paul Stevens argued that corporations are not members of society in the way individuals are and that the government has legitimate reasons to treat corporate political spending differently from the speech of human citizens. The dissent warned that allowing unlimited corporate and union spending could distort the political process and undermine public confidence in government. This clash between the majority and the dissent captured the central disagreement that has continued ever since.
Citizens United did not write on a blank slate. To reach its conclusion, the Court overruled two earlier decisions. The most important was Austin v. Michigan Chamber of Commerce, a 1990 ruling in which the Court had upheld a state law restricting corporate political expenditures. In Austin, the Court had accepted the argument that the government could limit the distorting effects of large amounts of corporate money in elections. Citizens United rejected that reasoning, holding that the government may not restrict speech in order to equalize the relative influence of different speakers.
The Court also overturned part of its 2003 decision in McConnell v. Federal Election Commission, which had upheld the electioneering communication restrictions of the McCain Feingold law. By reversing these precedents, Citizens United marked a significant shift in the Court's approach, moving away from the idea that the government may limit corporate spending to prevent distortion of the political process.
It is important to be precise about the scope of the ruling, because it is often described inaccurately. Citizens United addressed independent expenditures, meaning spending that is not coordinated with a candidate. It did not change the longstanding ban on direct corporate contributions to candidates. A corporation still may not write a check from its treasury directly to a candidate's campaign. What the decision allowed was for corporations and unions to spend their own money independently on political communications, such as advertisements supporting or opposing candidates.
The practical consequences became clear within months. Later in 2010, a federal appeals court applied the logic of Citizens United in SpeechNow.org v. FEC, holding that contributions to groups making only independent expenditures could not be limited. Together these decisions gave rise to the super PAC, an organization that can raise and spend unlimited amounts on independent political activity. In this way Citizens United, although it concerned corporate speech specifically, became the doorway to a much larger world of unlimited independent spending by many kinds of contributors.
Citizens United became a lightning rod for a broader argument about whether corporations should be treated as persons under the law. The idea that corporations have certain legal rights is not new. American courts have long recognized corporations as legal entities capable of owning property, entering contracts, and suing or being sued. A frequently cited example is an 1886 case, Santa Clara County v. Southern Pacific Railroad, in which a court reporter's note suggested that corporations were covered by certain constitutional protections, a notion that has been debated by historians ever since.
Supporters of the Citizens United decision argue that recognizing the speech rights of corporations protects the ability of all kinds of associations, including nonprofits, advocacy groups, and media companies, to speak about public issues. Critics argue that corporations are artificial entities created by law for economic purposes and that giving them the same political speech rights as individual citizens distorts democracy. This disagreement over corporate personhood is less a single legal question than a continuing philosophical debate about the proper role of organizations in the political life of a self governing people.
More than a decade after it was decided, Citizens United remains one of the most discussed and most contested decisions in modern constitutional law. Supporters see it as a robust defense of free expression that prevents the government from deciding who may speak about politics. Critics see it as a turning point that opened the door to vast sums of money in elections and made the original sources of that money harder to trace. Proposals to respond to the decision, including constitutional amendments and new disclosure laws, have been introduced repeatedly, though none has yet succeeded in altering the basic framework the case established. Whatever one's view, Citizens United is essential background for understanding why so much money now flows through independent channels, and why the debate over money in politics remains so intense.
See it in the data: The independent spending unleashed by this ruling shows up in real races. Follow the money in 2026 with our Campaign Finance Tracker.