As the 2026 U.S. midterm elections approach, an unprecedented volume of undisclosed political spending is reshaping battleground races across the country. Estimates indicate that roughly $1 billion in so-called dark money—funds from donors who remain anonymous—is being deployed this cycle, dwarfing previous levels and intensifying concerns about the influence of untraceable money in American politics.
Dark money refers to political expenditures made by nonprofit groups that are not required to disclose their donors. These groups, which often operate alongside related super PACs sharing staff and office space, funnel vast sums into advertising, direct mail, digital campaigns, polling, and grassroots efforts, making it difficult to ascertain the true sources of their funding.
This influx is particularly prominent in high-profile and competitive primary contests in states such as Michigan, Minnesota, Kansas, Texas, and Maine. In Michigan, for example, progressive candidate Dr. Abdul El-Sayed won a Democratic Senate primary despite being outspent by tens of millions in anonymous ads backing his opponent, Representative Haley Stevens. In Minnesota, a similar dynamic played out as large sums backed different candidates, while in Kansas a relatively unknown Democratic candidate received secret support exceeding his own campaign funds by a hundredfold. Texas witnessed Republican-linked nonprofits backing a Democratic nominee who had faced accusations of antisemitism, sparking controversy within her own party.
Republican and Democratic groups alike are leveraging legal loopholes to maximize hidden spending. They employ strategies such as funding ads through nonprofits allowed to keep donors anonymous, transferring money to allied super PACs without disclosing the original contributors, and creating “pop-up” super PACs that only report donors after elections, rendering disclosure ineffective for voters.
Four major nonprofit organizations aligned with both parties have been responsible for over $460 million of the dark money spending identified so far this cycle, a notable increase from $166 million spent in similar groups during the 2022 midterms. These entities often coordinate closely with their affiliated super PACs, effectively providing donors with ways to circumvent transparency.
Maine offers an illustrative example of dark money’s reach. Senator Susan Collins, a key Senate Appropriations Committee chairwoman whose re-election could influence control of the chamber, is facing an onslaught of nearly $75 million in undisclosed advertising from both sides. One Republican-aligned nonprofit, Stronger America Inc., has spent over $11 million supporting Collins and hosted fundraising events linked to prominent corporate donors. At the same time, Republican operatives have poured nearly half a million dollars into secretly influencing Democratic primaries, exemplified by efforts to unseat state senator Joe Baldacci.
Supporters of such undisclosed funding argue that anonymity is essential to protect free speech, particularly for donors with unpopular opinions or those fearing retaliation. Some critics, however, contend that the system enables undue influence by wealthy interests and undermines electoral accountability. They point to the scant enforcement capacity of regulatory agencies, with the Federal Election Commission lacking a quorum and the Internal Revenue Service limited in oversight due to staffing cuts.
The dark money landscape includes notable contributors such as the Koch family network and several environmental nonprofits, each spending tens of millions. Interest groups like the American Israel Public Affairs Committee have also played a role, particularly in races such as the Michigan Senate primary. One prominent actor, the American Prosperity Alliance, has refined techniques to obscure donor identities, employing an array of pop-up super PACs with deceptive names to sway multiple Democratic primaries.
Former President Donald Trump’s associated nonprofit, Securing American Greatness, has similarly spent tens of millions supporting Republican candidates and related super PACs. Both parties acknowledge privately that the current system permits significant undisclosed spending well beyond election day, with organizations advised to delay filing detailed reports until more than a year after voters cast their ballots.
As the midterms near, this surge of dark money highlights enduring tensions around campaign finance transparency, electoral integrity, and the power of private wealth in shaping political outcomes. Both advocates and opponents of secret spending agree that the scale and complexity of these operations pose challenges for regulators, voters, and candidates alike.