**Dark money** refers to political spending meant to influence elections or policymaking where the source of the funding is undisclosed or intentionally obscured. This lack of transparency makes it difficult for the public to know who is behind political ads, advocacy groups, or other election-related expenditures.

### Key Features of Dark Money:
1. **Anonymous Donors** – The true contributors are hidden from public disclosure, often through legal loopholes.
2. **Channeled Through Nonprofits or Shell Entities** – Dark money often flows through **501(c)(4) "social welfare" organizations**, trade associations, or LLCs that are not required to disclose donors.
3. **Used for Political Influence** – Despite nonprofit rules prohibiting *primary* political activity, dark money groups spend heavily on issue ads, voter mobilization, and other efforts that benefit specific candidates or parties.
4. **Legal but Controversial** – While some dark money spending is legal (especially after the *Citizens United* Supreme Court decision in 2010), critics argue it undermines democracy by allowing undisclosed special interests to sway elections.

### Why It Matters:
Dark money raises concerns about **accountability, corruption, and undue influence** in politics, as voters cannot assess potential conflicts of interest when funding sources are secret.