How Are Campaigns Funded: Donors, PACs, and Dark Money

Federal campaigns are funded by a mix of sources, some tightly capped and publicly disclosed, others essentially unlimited and sometimes anonymous. How campaigns are funded breaks down into six practical categories: individual donors, political action committees, party committees, the candidate’s own money, tax-exempt nonprofits that spend without naming their backers, and a public financing program that almost no one uses anymore. For the 2025–2026 cycle, an individual can give a candidate up to $3,500 per election, while Super PACs and certain nonprofits face no cap on what they raise or spend independently.¹

Individual Donors

Direct giving by private citizens is the largest funding source for most federal campaigns. Only U.S. citizens and lawful permanent residents may contribute; foreign nationals are barred entirely.²

For 2025–2026, an individual may give up to $3,500 to a single candidate per election. Because the primary and general elections each count as a separate election, one person can give a candidate a combined $7,000 across both contests. These caps are indexed for inflation and adjust every odd-numbered year.³

Campaigns must disclose the name, address, occupation, and employer of every donor whose aggregate contributions exceed $200 in a calendar year.⁴ Those reports are filed with the Federal Election Commission and are publicly searchable, so anyone can look up who is funding a candidate. Contributions do not have to be cash. Donated goods and services count as “in-kind” contributions valued at their fair market price, and they count against the same dollar limits as a check.⁵

If a candidate loses the primary or drops out before the general, any contributions already designated for the general must be refunded, redesignated, or reattributed within 60 days.³ Donors who give early to a long-shot candidate may see their general-election money come back.

PACs and Super PACs

A traditional political action committee pools money from members of a corporation, union, or trade group and directs it to candidates. Traditional PACs face a $5,000-per-candidate-per-election cap and must file itemized reports of every dollar received and spent. Corporate PACs, technically called “separate segregated funds,” can only solicit contributions from people connected to the sponsoring organization, such as employees, shareholders, or union members.⁶

Super PACs are a different animal. Created after the Supreme Court’s 2010 decision in Citizens United v. FEC, these independent-expenditure-only committees may raise unlimited amounts from individuals, corporations, and unions, and may spend without limit on ads and voter outreach.⁷ The one hard rule: a Super PAC cannot coordinate with any candidate’s campaign. No shared strategy sessions, no advance copies of ad scripts, no joint decisions about where to spend.⁸

In practice, the line between “independent” and “coordinated” has proven hard to police. Super PACs routinely hire former staffers of the candidates they support and rely on publicly posted strategy memos that campaigns make available without technically sharing them directly. Super PACs must still register with the FEC and disclose their donors, which is what distinguishes them from the dark-money vehicles discussed below.

Party Committees and Joint Fundraising

National, state, and local party committees raise and spend money that outlasts any single campaign. An individual can give up to $44,300 per year to a national party committee for 2025–2026, a much higher cap than any single candidate can accept.³ Party committees can transfer money to a candidate’s account or make “coordinated expenditures,” paying for polling, opposition research, or media production in consultation with the campaign.⁹ Coordinated expenditures have their own caps, adjusted annually based on the office sought and the state’s voting-age population.

Party money flows toward competitive races where an extra push could flip a seat. That strategic triage is one way parties maintain leverage: a member who bucks leadership risks seeing coordinated dollars redirected elsewhere.

Candidates and party committees often team up through joint fundraising committees, which run single events or solicitations and split the proceeds. A donor writes one large check, and the committee distributes it according to a pre-agreed formula. The written agreement must spell out each participant’s share, and every solicitation must disclose the allocation formula. If the formula would push a donor past the contribution limit for any one participant, the committee reallocates the excess to the others based on their proportionate shares.¹⁰ This is how a single $100,000 dinner ticket becomes legal: the money fans out across a candidate committee, a national party committee, and several state party committees, each receiving only what it is allowed to accept.

Candidate Self-Funding

Wealthy candidates can bankroll their own campaigns without limit. The Supreme Court established in Buckley v. Valeo (1976) that restricting how much of your own money you spend on your own speech violates the First Amendment.¹¹ A self-funder faces no contribution ceiling on personal funds.

Many self-funders structure their money as a loan to the campaign rather than an outright gift. If the campaign later raises enough from outside donors, it can repay the candidate. In 2022, the Supreme Court struck down a provision of the Bipartisan Campaign Reform Act that had capped repayment of personal loans using post-election contributions at $250,000, ruling the cap unconstitutionally burdened political speech.¹² There is now no federal dollar limit on how much a campaign can repay from post-election fundraising. Self-funding still carries real risk. If a campaign fizzles before generating outside support, the candidate absorbs the loss.

Dark Money Nonprofits

“Dark money” is political spending where the original donors stay hidden. The main vehicles are 501(c)(4) social welfare organizations and 501(c)(6) trade associations. Under the Internal Revenue Code, these nonprofits can engage in political campaigns as long as that activity is not their primary purpose.¹³ The IRS has never drawn a bright line defining “primary,” but the working rule of thumb among tax practitioners is that political spending should stay below roughly 40 percent of total expenditures.

Unlike Super PACs, these nonprofits report donor information only to the IRS, and even that requirement was rolled back by a 2018 Treasury rule eliminating donor-identity reporting on Schedule B for most tax-exempt organizations other than 501(c)(3) charities. A corporation or individual can write a seven-figure check to a 501(c)(4), and the public sees the ads but never learns who paid.

Dark-money groups cannot give directly to a candidate’s campaign committee, but they can run independent expenditure campaigns with unlimited budgets: attack ads, digital campaigns, and grassroots organizing.⁸ A common arrangement involves a dark-money nonprofit funneling money to a Super PAC, which then files disclosure reports listing the nonprofit as the donor. The donor behind the nonprofit stays anonymous. Layering like this is where most of the debate over campaign finance transparency is concentrated.

Public Financing

The federal government offers an alternative through the Presidential Election Campaign Fund. Taxpayers can direct $3 of their federal tax liability ($6 for joint filers) to the fund by checking a box on their return, at no extra cost to themselves.¹⁴ Primary candidates who qualify receive matching funds: the government matches up to $250 of each individual contribution, provided the candidate has raised more than $5,000 in matchable contributions in each of at least 20 states.¹⁵ General-election nominees from major parties can receive a lump-sum grant instead.

The catch: accepting public funds means accepting spending caps. No major-party presidential nominee has opted into the system since 2008, because private fundraising now dwarfs what the public fund can provide.

Some cities and states run their own programs. “Democracy voucher” programs give residents small-dollar certificates they can assign to qualifying candidates. Other jurisdictions run matching-fund programs that multiply small donations, amplifying small donors and reducing candidates’ dependence on wealthy contributors.

Who Cannot Give

Federal law bars several categories of would-be donors, and violations can carry criminal penalties.

Foreign nationals cannot contribute to, donate to, or spend independently on any federal, state, or local election. It is also illegal to solicit or accept such a contribution.¹⁶
Corporations and unions cannot give directly from their treasuries to a federal candidate’s campaign committee, although they can fund PACs and Super PACs.²
Federal government contractors, individuals and companies alike, are prohibited from contributing to federal candidates, though a corporate contractor’s employees can still give through a separate PAC.²
Straw donors, meaning anyone routing a contribution through someone else’s name to disguise the true source, commit a federal offense. Both the organizer and the person whose name is used can face legal consequences.

A campaign that knowingly accepts a prohibited contribution faces FEC enforcement, and willful violations can be referred to the Department of Justice for criminal prosecution.¹⁶

1
Federal Election Commission. Contribution Limits for 2025-2026
2
Federal Election Commission. Who Can and Can’t Contribute
3
Federal Election Commission. Contribution Limits
4
Office of the Law Revision Counsel. 52 USC 30104 – Reporting Requirements
5
eCFR. 11 CFR 104.13 – Disclosure of Receipt and Consumption of In-Kind Contributions
6
Federal Election Commission. Political Action Committees (PACs)
7
Federal Election Commission. Citizens United v. FEC
8
Federal Election Commission. Making Independent Expenditures
9
Federal Election Commission. Coordinated Party Expenditure Limits Adjusted for 2019
10
eCFR. 11 CFR 9034.8 – Joint Fundraising
11
Office of the Law Revision Counsel. 52 USC 30116 – Limitations on Contributions and Expenditures
12
Supreme Court of the United States. Federal Election Commission v. Ted Cruz for Senate
13
IRS. Political Campaign and Lobbying Activities of IRC 501(c)(4), (c)(5), and (c)(6) Organizations
14
Federal Election Commission. Presidential Election Campaign Fund Tax Check-Off Chart
15
eCFR. Part 9033 – Eligibility for Payments
16
Office of the Law Revision Counsel. 52 USC 30121 – Contributions and Donations by Foreign Nationals