Federal elections now cost billions of dollars each cycle, with the 2024 elections setting records. Money comes from individual donors, political action committees, parties, self-funding candidates, and outside groups, under rules shaped by Congress and, even more, by the Supreme Court's reading of the First Amendment.
This guide explains who can give, how much, what must be disclosed, the agency that enforces the rules, the key court decisions, and the arguments over reform.
Supporters of current law and of further deregulation argue that spending money to spread political views is core free speech, that limits protect incumbents, and that voters can judge messages for themselves. Reform advocates argue that large donors gain outsized influence and access, and they propose stronger disclosure, small-donor matching programs, a restructured FEC, or a constitutional amendment to overturn Citizens United. Many states have their own limits and public financing programs for state races.
The Tillman Act of 1907 banned corporate contributions to federal candidates, and later laws extended limits to unions. After the Watergate scandal revealed secret cash contributions, Congress amended the Federal Election Campaign Act in 1974 to cap contributions and spending, require disclosure, create public financing for presidential races, and establish the Federal Election Commission. The Bipartisan Campaign Reform Act of 2002, known as McCain-Feingold, banned unlimited soft money contributions to national parties.
Super PACs may accept unlimited contributions from individuals, corporations, and unions and spend unlimited amounts, as long as they do not coordinate with candidates. Nonprofit groups organized as social welfare organizations can also spend on politics without disclosing their donors, which critics call dark money. On June 30, 2026, in NRSC v. FEC, the Supreme Court struck down limits on spending that political parties coordinate with their own candidates, overruling a 2001 precedent. Supporters said the ruling strengthens parties against outside groups, while critics said it opens a new path for large donors to support candidates.
Individuals may give a set amount to each candidate per election, adjusted every two years for inflation, and larger amounts to national party committees. Traditional political action committees, including those formed by corporations and unions, collect voluntary contributions from employees or members and give limited amounts to candidates. Candidates may spend unlimited amounts of their own money. Foreign nationals are barred from contributing or spending in U.S. elections. The presidential public financing system still exists but has not been used by a major-party nominee in the general election since 2008.
Candidates, parties, and PACs must file regular reports with the Federal Election Commission listing donors who give more than 200 dollars, and the reports are public online. The FEC has six commissioners, no more than three from one party, and needs four votes to act, which often produces deadlocks. It lost its quorum in April 2025 after resignations and could not issue rules, advisory opinions, or penalties, and two nominees were sent to the Senate in February 2026. Criminal violations are prosecuted by the Justice Department.
In Buckley v. Valeo in 1976, the Supreme Court held that limits on contributions are constitutional to prevent corruption, but limits on campaign spending and independent expenditures violate the First Amendment. In Citizens United v. FEC in 2010, it held that corporations and unions may spend unlimited amounts independently, and a federal appeals court ruling the same year, SpeechNow.org v. FEC, opened the way for super PACs. McCutcheon v. FEC in 2014 struck down aggregate limits on how much one donor can give to all candidates combined.
See how campaigns unfold in the presidential election, start to finish, learn who influences policy between elections in lobbying explained, or see how elections are administered in who runs elections in America.