Super PACs closely aligned with Democratic and Republican congressional leaders have disclosed record donations from affiliated “dark money” groups, obscuring the source of hundreds of millions of dollars influencing House and Senate midterm elections next week.

This torrent of secret money exploits a provision in federal election law that allows super PACs, which must publicly disclose the identities of their contributors, to accept donations from certain nonprofits, trade groups, unions and shell corporations, which themselves are generally exempt.

Dark money groups have for years given tens of millions of dollars to Republican super PACs Senate Leadership Fund and Congressional Leadership Fund and Democratic super PACs Senate Majority PAC and House Majority PAC.

But this election cycle, these dark money affiliates have collectively donated more than $392 million to the four leadership-aligned super PACs as of Oct. 14, according to a Washington Sun analysis of Federal Election Commission data.

That’s more than double the $181.9 million these super PACs reported receiving through the same period in the 2024 election cycle, a previous record.

Not only are these four super PACs receiving more total donations from their dark money affiliates than in any previous election cycle, but those dark donations make up a greater percentage of the super PACs’ overall fundraising than ever before, according to The Sun’s analysis.

Super PACs are “super” because they are legally allowed to raise and spend unlimited amounts of money to advocate for and against political candidates, although they cannot directly donate money to candidates’ own campaigns. They’re also restricted in how they may coordinate their efforts with candidate committees.

The congressional leadership-aligned super PACs are currently four of the five largest outside spenders this election cycle, according to OpenSecrets, a nonpartisan nonprofit that tracks the flow of money in American politics.

Republicans’ Senate Leadership Fund is chief among them, having received more than $132.9 million from the dark money nonprofit group One Nation as of Oct. 14, according to FEC data.

That’s a 148% increase from the $53.6 million One Nation steered into the Senate Leadership Fund during the 2024 election cycle. Before that, the most money that the Senate Leadership Fund reported receiving from One Nation through the same period was $62.6 million during the 2020 election cycle.

While One Nation and the Senate Leadership Fund are technically separate entities, their logos hung side by side in the entryway of a Washington office that The Sun visited in November.

And Republicans’ Congressional Leadership Fund disclosed sending its affiliated dark money group, American Action Network, $329,670 as “reimbursement for shared labor, rent, utilities,” according to its latest report to the FEC, indicating some shared operations.

The Congressional Leadership Fund reported receiving around $64 million from American Action Network so far this election cycle, according to FEC data, a nearly 60% surge from $40 million at the same point during the 2024 cycle. The Senate Leadership Fund and Congressional Leadership Fund did not respond to requests for comment.

On the left, the total amount of dark money flowing into Democratic super PACs Senate Majority PAC and House Majority PAC has more than doubled from the 2024 election cycle, according to FEC data.

As of Oct. 14, Senate Majority PAC has reported receiving $102 million from its affiliated dark money group, Majority Forward. That’s up from about $45 million through the same period during the 2024 election cycle and $48 million during the 2022 election cycle.

Around 29% of the money that the Senate Majority PAC has raised through the same period has come from Majority Forward — up from 14% through the same period in 2024, 19% in 2022 and 3% in 2020.

And House Majority PAC has reported receiving $93.7 million from House Majority Forward, up from $42.5 million during the 2024 election cycle and $7 million during the 2022 election cycle.

House Majority Forward accounted for 32% of all the money House Majority PAC has raised as of Oct. 14. That’s up from 19% of all fundraising through the same point in the 2024 election cycle and 5% through the same period in both the 2022 and 2020 election cycles, according to The Sun’s analysis of FEC data.

House Majority PAC declined to comment. The Senate Majority PAC did not respond to requests for comment.

Some congressional Democrats have pushed — unsuccessfully — for legislation that would require greater disclosure of dark money donations.

But the Democrats’ two congressional leadership-aligned super PACs have nevertheless invited donations through their dark money groups more and more over the last few election cycles.

“While Democrats in Congress continue to push for reforms to bring more transparency to political spending to end dark money, there’s a lot of Democratic operatives out there who say the party needs to fight fire with fire, and there are politicians who’ve been willing to embrace that,” Michael Beckel, money in politics reform director at Issue One, told The Sun.

The Republican-aligned super PACs are also bringing in a greater percentage of their overall fundraising from affiliated dark money groups than they have in previous election cycles, although both super PACs embraced these donations a bit earlier than their Democratic counterparts.

One Nation made up more than 24% of all donations to the Senate Leadership Fund as of Oct. 14, according to FEC data. That’s up from 19% through the same period in 2024, 21% in 2022 and 20% in 2020.

Around 25% of the Congressional Leadership Fund’s fundraising as of Oct. 14 came from American Action Network — up from 17% through the same period in 2024, 19% in 2022 and 18% in 2020.

Beyond the four congressional leadership super PACs, many other super PACs follow a similar playbook: More than $1 billion in dark money had already poured in the 2026 midterms by the end of August, when The New York Times published an analysis that included political advertising data and tax filings in addition to campaign finance disclosures.

Few of the House and Senate races that will determine control of Congress are untouched by dark money, which is sometimes passed through multiple nonprofits and political groups before getting spent in the form of political attack ads or mailers.

Take, for instance, the U.S. Senate race in Michigan. Undisclosed donors gave money to the nonprofit Right Vote, which then gave to conservative super PAC Sentinel Action Fund, which in turn spent more than $1.6 million against Democrat Abdul El-Sayed across 12 expenditures.

Undisclosed donors also gave an undisclosed amount of money to Senate Opportunity Fund, a nonprofit that doesn’t disclose its donors, which gave to High Plains PAC, which spent $258,000 against El-Sayed across three payments.

Meanwhile, mystery donors gave to Majority Forward and the Economic Opportunity Fund, which gave to the Senate Majority PAC, which then gave to pro-Democratic super PAC WinSenate, which spent over $9 million against the Republican nominee in Michigan, former Rep. Mike Rogers.

El-Sayed has also benefited from a trail of dark money to the Senate Majority PAC, which in turn gave to WinSenate, which spent in support of the Democrat. Right Vote gave $5 million to the Sentinel Action Fund, which spent $1.45 million total in support of Rogers.

In Maine, dark money is being spent to support and oppose Republican Sen. Susan Collins and her democratic challenger, Troy Jackson. Sentinel Action Fund sent $1.5 million to the Lead Maine Committee, which has spent around $370,000 supporting Collins. WinSenate has spent nearly $4.5 million in support of Jackson.

“The amount of money that are being pumped into elections this cycle is just off the charts compared to previous years, and I think a lot of voters all across the political spectrum are looking for politicians to actually de-escalate the political fundraising arms race,” Beckel told The Sun.

Voters across the political spectrum generally believe there is too much money in politics, a frustration some Republican and Democratic candidates have been leaning into this election cycle.

But to date, Democrats and Republicans have been unwilling to coalesce around bipartisan reforms to change the way national elections are funded. The Supreme Court, for its part, has made it easier this election cycle for party committees to spend unlimited sums in coordination with candidates — and access lower television and radio advertising prices, which are not available to super PACs.