Outside spending on 2024 federal elections has hit a record $4.5 billion, with more than half of that spending coming from groups that do not fully disclose the source of their funding. 

Independent political committees like super PACs, which can raise and spend unlimited sums but must disclose their donors to the Federal Election Commission, have reported receiving over $1 billion from shell companies and “dark money” groups like nonprofits that do not — and are not required to — disclose their donors. 

During the 2022 midterm cycle, OpenSecrets documented $617 million in contributions from groups with anonymous donors while the last presidential cycle attracted $653 million. That represents a substantial jump from the 2016 election when shell companies and dark money groups contributed less than $71.7 million to federal political committees. 

Outside spending on the 2024 presidential race pitting Vice President Kamala Harris against former President Donald Trump has soared to a historic high of over $2 billion — marking the most expensive U.S. election in history, even when adjusted for inflation. Prior to this year, the most expensive election in U.S. history was the 2020 presidential race when about $1.14 billion was spent by outside groups. 

The record-breaking spending on the 2024 presidential race has been driven by super PACs allied with both major party candidates — and fueled by dark money from anonymous sources.

The cycle’s top spender is Future Forward USA PAC, a hybrid PAC supporting Harris that has reported spending about $517.1 million on the presidential race with hundreds of millions of that attacking Trump in the final weeks of the election cycle.

Several major donors reportedly threatened to pause contributions to the hybrid PAC after President Joe Biden’s debate performance in June but money poured in after Harris entered the race. 

Future Forward is required to disclose donors to the FEC but its top donor is a closely-tied dark money group, Future Forward USA Action, leaving the ultimate source of over $136.4 million of its funds unknown. 

As a 501(c)(4) nonprofit organization, Future Forward USA Action is not legally required to disclose its donors and does not voluntarily do so. But investigations have revealed some of the dark money group’s funding sources. 

Billionaire media mogul Mike Bloomberg reportedly gave $50 million to Future Forward’s nonprofit arm, according to reporting by the New York Times, along with another $19 million to the hybrid PAC this cycle. 

Future Forward’s PAC has also received $10 million from Democracy PAC, a super PAC funded entirely by billionaire megadonor George Soros and gains on the money it has invested. Open Society Policy Center, a nonprofit funded by Soros, has also disclosed steering money to Future Forward USA Action with $20 million during the 2022 election cycle. 

In addition to the substantial funding it has received from Future Forward USA Action, other major donors reported by Future Forward’s PAC include billionaire LinkedIn founder Reid Hoffman, who gave $10 million. Dustin Moskovitz, another billionaire internet entrepreneur who co-founded Facebook, has given $38 million to the hybrid PAC.

While Democrats have one dominant hybrid PAC outspending all other political groups boosting Harris in the presidential race, Trump has several major spenders boosting his run. Trump’s main super PAC, Make America Great Again Inc. has spent about $377 million boosting Trump or opposing his rivals. 

The top donor to MAGA Inc. is billionaire Timothy Mellon, heir to Gilded Age industrialist Andrew Mellon. Timothy Mellon gave $151.5 million to the pro-Trump super PAC through mid-October, according to OpenSecrets’ analysis of new FEC disclosures.

America PAC, a pro-Trump super PAC created by billionaire Elon Musk, has spent over $169 million on the 2024 presidential race after ramping up spending in the final weeks of the election. Musk poured about $118.6 million into the group since the summer with $43.6 million of that in October alone. 

Another top spender is the pro-Trump Preserve America PAC, which is funded primarily by Miriam Adelson, the wife of the late casino billionaire and conservative megadonor Sheldon Adelson. Preserve America PAC has spent over $112.2 million on ads primarily attacking Harris this cycle and received about $100 million of that from Adelson. Elizabeth Uihlein, who founded Wisconsin-based shipping and packaging materials company Uline along with her husband, Richard, chipped in another $3 million in October.

Billionaire shipping supply magnate Richard Uihlein steered another $53 million into his super PAC, Restoration PAC, since August. The Uihleins have come to prominence in recent years as conservative megadonors, pouring about $138 million into federal political groups spending on 2024 elections.

The Uihleins’ main super PAC, Restoration PAC, has spent about $35 million boosting Trump and attacking Harris in the 2024 presidential race. The super PAC spent another $4.6 million attacking Sen. Tammy Baldwin (D-Wisc.) and $3.1 million opposing Rep. Jared Golden (D-Maine), and doled out millions more to other groups spending to further the Uihlein’s agenda. 

Right for America has spent about $69.6 million boosting Trump in the 2024 presidential race. The super PAC’s top funders are former chairman and CEO of Marvel Entertainment Isaac Perlmutter and his wife, Laura. Perlmutter is a longtime Trump associate who advised him on Veterans Affairs policies during his first term.

Most expensive Senate races in U.S. history

When it comes to outside spending, the top six most expensive races in U.S. history are presidential races dating back to 2004. Pennsylvania’s 2022 Senate race and Georgia’s 2022 Senate race are also in the top 10 most expensive races, as measured by outside spending. 

Outside groups have poured more than $308 million into Ohio’s 2024 Senate election, making it the most expensive congressional race of the cycle and in the top 10 races in U.S. history. 

In Ohio, incumbent Sen. Sherrod Brown (D-Ohio) faces off with Republican challenger Bernie Moreno. The main super PAC supporting Brown is WinSenate PAC, which has spent over $79 million on the race. The super PAC was created in January and is funded entirely by Senate Majority PAC, the main outside group aligned with Senate Democrats. 

Senate Leadership Fund, the main outside group aligned with Senate Republicans, is the top supporter of Moreno and has spent about $71 million on the race. 

The two party-aligned super PACs are also top spenders targeting Pennsylvania’s Senate election. Outside spending on the race has reached $240 million, putting it in the top 12 elections of all time.

Democrats, party-aligned groups drive up dark money

Super PACs aligned with each major party’s leaders in the House and Senate have taken hundreds of millions of dollars from dark money groups funded by anonymous donors during the 2024 cycle. 

During the 2024 election cycle, the four main nonprofits aligned with Republicans and Democrats in Congress churned about $250 million from anonymous donors to allied super PACs. 

Senate Democrats’ flagship dark money group, Majority Forward, accounted for over $113.2 million of that, more than any prior election. The dark money group’s previous record for federal contributions was set in the 2022 midterm cycle with about $76 million total.

More than half of Majority Forward’s 2024 contributions — about $70.8 million — have gone to Senate Majority PAC, the main super PAC aligned with Senate Democrats, with $30 million of that in the third quarter of 2024 alone. The super PAC has yet to report any independent expenditures this cycle. Instead, Senate Majority PAC has steered money to the affiliated WinSenate PAC. 

Since its creation earlier this year, the new super PAC reported spending about $309 million on Senate races in key battleground states, including Arizona, Maryland, Michigan, Montana, Nevada, Ohio, Pennsylvania and Wisconsin. 

Duty and Country, another super PAC aligned with congressional Democrats that has been active in recent elections, has also received millions in funding from Majority Forward. 

The super PAC was created ahead of the 2020 election and previously funded by Duty and Honor, a 501(c)(4) nonprofit dark money group funded by and affiliated with Majority Forward. But IRS filings indicate that the dark money appendage has since shuttered. Majority Forward is now the super PAC’s sole donor with over $4 million in contributions this cycle. Duty and Country has used those funds to bankroll ads targeting Ohio’s record-shattering Senate race. 

Majority Forward is also the sole donor funding Last Best Place PAC, a super PAC spending millions on ads targeting Montana’s Senate race. The dark money group steered $38.4 million million to the super PAC through mid-October with $9 million of that in the first two weeks of October alone. 

Last Best Place PAC has spent over $33.8 million attacking former Navy SEAL and entrepreneur Tim Sheehy and boosting incumbent Sen. Jon Tester (D-Mont.) since its creation in 2023. But the independent expenditures reported by Last Best Place PAC are just one part of its campaign against Sheehy. 

The super PAC’s early advertising explicitly mentioned Sheehy’s Senate campaign but some ads did not expressly advocate for his election or defeat and were not reported to the FEC as independent expenditures to the FEC. Instead, all of its spending was lumped together as operating expenditures. In September, the nonpartisan Campaign Legal Center sued the Federal Election Commission alleging commissioners wrongfully dismissed complaints it had filed against Last Best Place PAC for failing to file required disclosures about some of its ads. 

Majority Forward’s counterpart boosting Democrats in the lower chamber of Congress, House Majority Forward, has also ramped up giving in the final months of the election cycle. 

The dark money group routed $43 million to the similarly-named House Majority PAC, the main super PAC aligned with House Democrats during the third quarter of this year. House Majority PAC’s 2024 spending has totaled over $196.1 million. 

The main 501(c)(4) nonprofit aligned with Senate GOP leadership, One Nation, has given about $54 million to Senate Leadership Fund. The super PAC, which is allied with Senate Republican leadership and shares resources with the dark money group, has spent over $211 million boosting Senate Republicans during the 2024 cycle.

American Action Network, a 501(c)(4) group aligned with House Republican leadership, has steered another $40 million in contributions from anonymous donors to the Congressional Leadership Fund. The hybrid PAC, which is also associated with GOP House leadership, has spent nearly $216.7 million to boost congressional Republicans this cycle.


Researcher Andrew Mayersohn contributed to this report.