A clarifying constitutional point

Citizens United v. FEC (2010) is often described as a ruling that legalized unlimited political spending. That is approximately correct. The Court held that independent expenditures by corporations on political speech could not be capped consistent with the First Amendment.

What Citizens United did not do is rule that political spending cannot be disclosed. The Court was explicit on this point. Justice Kennedy’s majority opinion noted that “disclosure permits citizens and shareholders to react to the speech of corporate entities in a proper way” and that “transparency enables the electorate to make informed decisions and give proper weight to different speakers and messages.”

This distinction matters because the policy debate about unaccountable money in US politics is sometimes framed as if disclosure laws would face the same constitutional headwinds as spending caps. They do not. Disclosure has been upheld by the Supreme Court repeatedly, including in Citizens United itself.

What “dark money” actually refers to

The term is used loosely. The structural picture is more precise.

Federal political spending in the US flows through several distinct vehicles, with very different disclosure requirements:

• Candidate campaigns must disclose donors above $200 and expenditures above similar thresholds. Detailed reports filed with the FEC.
• Party committees (DNC, RNC, congressional and state party committees) must disclose donors and expenditures.
• Federal PACs (the traditional kind, with contribution limits) must disclose donors and expenditures.
• Super PACs — created after Citizens United and SpeechNow — can raise and spend unlimited sums but must disclose donors. The “unlimited” applies to amounts; donor identity is public.
• 501(c)(4) “social welfare” organizations can engage in some political activity (not as their “primary purpose”) and do not have to disclose donors to the public. They report donor identities only to the IRS.
• 501(c)(6) trade associations operate under similar non-disclosure rules.
• LLCs can donate to super PACs without revealing the actual sources of their funds, creating a disclosure-laundering pathway.

“Dark money” refers primarily to the third-to-last category — political spending by 501(c)(4)s and similar entities whose donors are not public. By many estimates, roughly half of federal political spending in recent cycles flows through dark-money channels in some form.

The DISCLOSE Act and its descendants

The DISCLOSE Act (Democracy Is Strengthened by Casting Light On Spending in Elections) has been introduced in every Congress since 2010. The 2022 version came closest to passage; it failed cloture in the Senate.

The current version of the DISCLOSE Act would:

• Require 501(c)(4) and 501(c)(6) organizations spending over $10,000 on federal political activity to disclose donors above a threshold (typically $10,000).
• Apply disclosure to electioneering communications close to elections, not just direct candidate advocacy.
• Require disclosure of major donors in the political ads themselves (“stand by your ad”-style requirements for top funders, not just the sponsoring organization).
• Require government contractors to disclose political spending.
• Pierce LLC structures used to obscure donor identity.

The bill survives constitutional scrutiny because it is, in legal terms, a disclosure regime, not a contribution or expenditure cap. The Supreme Court has consistently distinguished disclosure from caps and applied lower scrutiny to the former.

The political opposition to the bill is substantial because the donors who currently use dark-money channels do so precisely to avoid public accountability. Disclosure does not stop their giving; it just makes it visible.

What state-level disclosure has achieved

Several states have implemented disclosure regimes that go meaningfully beyond federal law:

Montana has long required disclosure of major political spending. Its 2012 American Tradition Partnership litigation (overturning Montana’s century-old corporate political spending ban) was the case that confirmed Citizens United applies to state law. Disclosure rules survived.

California requires disclosure of major donors to ballot-measure committees and has expanded similar rules to candidate-related spending. The California rules have produced visible enforcement — the state has imposed fines and required disclosure in cases where donor-identity laundering was attempted.

New York has expanded disclosure rules, including for entities funding state-level political activity.

Maryland and Connecticut have implemented disclosure rules for state contractors’ political spending.

The empirical record from these states suggests disclosure has measurable effects:

• It discourages a portion of dark-money giving (donors who valued anonymity choose not to give once disclosed).
• It enables press, opposition campaigns, and watchdog groups to surface conflicts of interest.
• It has not, contrary to industry warnings, deterred large amounts of legitimate political activity.

The Treasury and IRS lever

A separate disclosure path runs through the IRS. 501(c)(4) organizations must file Form 990 with the IRS, including major donor information on Schedule B. That information is not publicly available, but the IRS has it.

A 2018 Treasury rule eliminated the requirement that 501(c)(4)s and 501(c)(6)s report donor identities to the IRS at all. A 2020 court ruling vacated that rule on procedural grounds. The Biden Treasury restored donor reporting but did not make it public.

The path forward through the IRS lever is narrow but real. It includes:

• Restoration and protection of donor reporting requirements at the IRS level.
• Enhanced IRS enforcement against 501(c)(4)s whose primary purpose is political (rather than the “social welfare” the tax-exempt status nominally requires).
• Coordination between IRS data and FEC data to flag suspicious patterns.

Local-level options

Several cities have implemented disclosure rules for local elections. Seattle’s “I-122” democracy voucher program and disclosure regime, San Francisco’s lobbyist and contractor disclosure rules, and various municipal pay-to-play rules represent the local frontier of money-in-politics regulation.

Local disclosure cannot substitute for federal disclosure of federal political spending, but it provides experimental ground for new approaches and can shift the political acceptability of broader reform.

What to watch

• DISCLOSE Act reintroduction and floor consideration. Senate procedural posture remains the binding constraint.
• State-level disclosure expansion. Active in NY, NJ, MA, MD, others.
• Treasury and IRS rulemakings. Donor-reporting requirements remain technically discretionary; protections worth tracking.
• Litigation defending state disclosure rules. Several state regimes face ongoing constitutional challenges; outcomes shape what’s possible elsewhere.
• Local pilots. Seattle, San Francisco, New York, others. Worth watching for innovations.
• Constitutional amendment proposals. A number of versions overturning Citizens United exist; none have advanced. The shifting Supreme Court composition keeps the underlying doctrine in long-term play.

Bottom line

Dark-money disclosure is the most achievable structural reform on money in politics. It does not require constitutional amendment. It does not face the same Supreme Court doctrine that blocked contribution and expenditure caps. It is opposed primarily by the donors and entities whose anonymity it would end — which is exactly why it is hard, and exactly why it is worth pursuing.