Citizens United
A 2010 Supreme Court ruling changed how money moves through U.S. elections. Here's exactly what it decided, and what the disclosed numbers show about who's spent what since.
Last updated September 22, 2026
Terms
- Independent expenditure
- Money spent on ads or messages supporting or opposing a candidate, made without coordinating with that candidate's own campaign — the specific category of spending Citizens United ruled corporations and unions can't be banned from making.
- Super PAC
- A political committee that can raise and spend unlimited money on independent expenditures, so long as it doesn't give directly to candidates or coordinate with their campaigns. Created by a related 2010 court ruling, not Citizens United itself.
- Dark money
- Political spending by nonprofits that aren't required to disclose their donors, so the public sees the spending but not who paid for it.
What the ruling actually decided
On January 21, 2010, the Supreme Court ruled 5–4 in Citizens United v. FEC that the government can't ban corporations and labor unions from spending their own money on independent expenditures — ads and messaging that support or oppose a candidate without coordinating with that candidate's campaign. The Court held that this kind of spending is protected political speech under the First Amendment, and struck down the part of a 2002 campaign finance law that had banned it.
What didn't change: corporations still can't give money directly to a candidate's campaign — that limit stayed in place and still applies today. Political ads still have to disclose who paid for them. Citizens United itself didn't create Super PACs either; a related D.C. Circuit ruling later that year, SpeechNow.org v. FEC, applied the same logic to say contribution limits on groups that only make independent expenditures were unconstitutional too — which is what actually opened the door to committees that can raise unlimited sums from individuals, corporations, and unions alike, so long as they spend independently of any campaign.
The money since
- Total federal election spending, 2008 (inflation-adjusted)
- $7.1B
- Total federal election spending, 2024
- $15.9B
- Super PAC spending, 2010–2022 combined
- $6.4B
- Super PAC spending, 2024 alone (record)
- $2.7B
Brennan Center for Justice; OpenSecrets.
Total spending across federal races roughly doubled between the election before the ruling and the 2024 cycle, even after adjusting for inflation. Dark money grew even faster in percentage terms: less than $5 million in 2006, to more than $1 billion in the 2024 presidential race alone — and that $1 billion-plus was spent by groups that, by definition, didn't have to say where it came from.
How concentrated it is
In the 2022 midterms, just 21 wealthy donor families gave a combined $0.8B — and billionaires accounted for 15% of all federal election financing that cycle. In 2024, the top 10 donors to Donald Trump's campaign accounted for 44% of all the money behind him ($0.5B); the top 10 donors to Kamala Harris accounted for 8% of hers ($0.1B).
The biggest individual donors of the 2024 cycle
Total reported political giving, 2023–2024 cycle, per FEC filings — OpenSecrets.
Nonpartisan, plainly
We don't take a position on whether Citizens United was rightly decided, whether Super PACs or dark money should be restricted further, or whether campaign finance limits help or hurt democracy — those are real disagreements, argued by serious legal scholars and elected officials on more than one side, going back to the case itself (a 5–4 decision, not a unanimous one). What isn't in dispute: what the ruling held, and what the disclosed spending numbers actually show. These are the facts, plainly. See also our page on AIPAC's super PAC spending, a specific example of independent-expenditure money at work in primaries.
Talking points
These are the questions we think you should ask those who are running for office and will represent you. We don't give our opinion on the answer, but we DO think you should be talking about them.
- Should Congress pursue a constitutional amendment to overturn Citizens United, and what should replace it?
- Should super PACs be required to disclose their donors in real time rather than on a periodic filing schedule?
- Should there be a legal cap on how much a single donor can give to a super PAC, closing the "dark money" gap?
- Should publicly funded elections — matching small donations with public funds — be expanded as an alternative to unlimited outside spending?
Read more
- FEC: Statement on the Supreme Court's decision in Citizens United v. FECfec.gov
The federal agency's own summary of what the ruling changed.
- Brennan Center: Citizens United, Explainedbrennancenter.org
The dark-money, super PAC, and billionaire-share figures below.
- Brennan Center: Fifteen Years Later, Citizens United Defined the 2024 Electionbrennancenter.org
The 2024-specific donor-concentration figures below.
- OpenSecrets: Elon Musk tops list of 2024 political donorsopensecrets.org
The individual donor totals in the chart above, from FEC filings.
- OpenSecrets: Total 2024 election spending projected to exceed previous recordopensecrets.org
The total-cost-of-elections figures cited above.