The financing of electoral campaigns in the United States happens at the federal, state, and local levels by contributions from individuals, corporations, political action committees, and sometimes the government. Campaign spending has risen steadily at least since 1990 (for example the average campaign spending for a candidate who won an election to the House of Representatives in 1990 spent $407,600, while the average winner thirty years later spent $2.35 million (approximately $1 million adjusted for inflation); in the Senate, average spending for winning candidates went from $3.87 to $27.16 million (about $13.71 million adjusted for inflation)).
In 2020, nearly $14 billion was spent on federal election campaigns in the United States -- "making it the most expensive campaign in U.S. history", "more than double" what was spent in the 2016 election. Critics complain that following a number of Supreme Court decisions -- Citizens United v. FEC (2010) in particular—the "very wealthy" are now allowed to spend unlimited amounts on campaigns (through Political Action Committees, especially "Super PACs"), and to prevent voters from knowing who is trying to influence them (contributing "dark money" that masks the donor's identity). Consequently, as of at least 2022, critics (such as the Brennan Center for Justice) allege "big money dominates U.S. political campaigns to a degree not seen in decades" and is "drowning out the voices of ordinary Americans."
Public concern over the influence of large donors in political campaigns was reflected in a 2018 opinion poll which found that 74% of Americans surveyed thought it was "very" important that "people who give a lot of money to elected officials" "not have more political influence than other people", but that 72% thought this was "not at all" or "not too" much the case. Another 65% of respondents agreed that it should not be impossible to change this and that "new laws could be written that would be effective in reducing the role of money in politics".
Laws regulating campaign donations, spending and public funding have been enacted at the federal level by the Congress and enforced by the Federal Election Commission (FEC), an independent federal agency. Nonprofit, non-governmental grassroots organizations like the Center for Responsive Politics, Consumer Watchdog and Common Cause track how money is raised and spent. Although most campaign spending is privately financed (largely through donors that work in subsidized industries), public financing is available for qualifying candidates for President of the United States during both the primaries and the general election. Eligibility requirements must be fulfilled to qualify for a government subsidy, and those that do accept government funding are usually subject to spending limits on money.
Races for non-federal offices are governed by state and local law. Over half the states allow some level of corporate and union contributions. , some states have stricter limits on contributions, while some states have no limits at all. Much information from campaign spending comes from the federal campaign database which does not include state and local campaign spending.
Terminology, definitions
"campaign funds" are (legally) defined by the Federal Election Campaign Act as funds "used for purposes in connection with the campaign to influence the federal election of the candidate" (see below). "Dark money": spending to influence elections where the source of the money is not disclosed to voters (see below). Soft Money: money that is not supposed to "advocate the election or defeat of a federal candidate", but instead to be used for "state and local elections and generic 'party-building' activities, including voter registration campaigns and get-out-the-vote drives". Unlike hard money, there are "no federal contribution limits" on it (see below). Hard Money: "regulated contributions (see below) "from an individual or PAC to a federal candidate, party committee or other PAC, where the money is used for a federal election"
Campaign spending
Money spent on campaigns in the 21st century has risen somewhat faster than inflation over time. Total cost of Federal elections, Congressional and Presidential (1990-2022) (In billions of dollars, adjusted for inflation. Source: OpenSecrets)