A surge of 22 late-forming super PACs had reported roughly $637 million in independent expenditures in US congressional races by Oct. 29, according to a CNBC analysis of Federal Election Commission filings. The groups, all registered in the final 10 weeks before Election Day and each spending at least $1 million, accounted for about one-sixth of all independent spending in House and Senate races.
Federal law requires super PACs and political committees to report large independent expenditures within 24 or 48 hours, depending on how close to Election Day the spending occurs, but donors are disclosed less frequently through periodic reports. For example, Our Heritage Matters registered with the FEC on Oct. 15, after a key campaign finance reporting deadline, so its first regular report identifying its donors is not due until Dec. 3, a month after Election Day.
The tactic has exploded in 2026. At the same point in the 2022 midterms, just five comparable groups had spent about $18 million combined. In 2018, three had spent about $12 million. The total has even exceeded combined spending by such groups in congressional races during the 2020 and 2024 presidential elections, CNBC found.
Republicans have used the strategy more heavily: Republican-linked PACs have spent about twice what Democratic-linked ones have disbursed. The largest spender among the late-forming groups is No Going Back PAC, formed Sept. 1, which has spent roughly $242.2 million and is tied to President Donald Trump's MAGA Inc. super PAC. Another is Texas PAC, formed Aug. 28, which has spent about $181.6 million to support Republican Ken Paxton in Texas' Senate race. Its funding came through the Senate Leadership Fund, the GOP's main Senate super PAC. FEC filings showed Musk had given the fund $158 million in two contributions, with the group transferring matching amounts to Texas PAC the day after each donation.
On the Democratic side, Lower Costs Now formed Sept. 10 and had spent about $75.5 million in eight Senate contests. Its first regular report showed Senate Majority PAC had given the group $23 million. Texas Forever, launched Sept. 24, had spent about $27.5 million to help Democratic Senate nominee James Talarico.
Fourteen of the 22 groups spent all their money in a single congressional contest. The Maine Standard, formed Sept. 11, spent $8.2 million all opposing Democrat Troy Jackson in Maine's Senate race. The Cornhusker Majority, formed Sept. 10, has spent about $7.1 million in Nebraska's Senate race, almost all opposing independent Dan Osborn.
“The reason for this is almost entirely to avoid disclosure, even if just temporarily,” said Michael Kang, a Northwestern Pritzker School of Law professor who studies campaign finance. “Many times, if the donors were known, then it would undercut their cause.”
Saurav Ghosh, director of federal campaign finance reform at the Campaign Legal Center, said: “It’s happening more often, and they’re spending more money doing it because it works, and they’re getting away with it.”
Hilary Braseth, executive director of OpenSecrets, said that while a locally branded PAC does not necessarily hide funding sources, it “fragments the picture,” making it harder for voters to see the national organizations behind the spending.
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Late-forming super PAC spending on midterm races by year (as of Oct. 29)
US$ million
Super PACs formed in the final 10 weeks before Election Day that spent at least $1 million on House or Senate races. 2020 and 2024 presidential election years are not shown here. Source: CNBC analysis of FEC filings
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Analysis
Why This Matters
Voters cannot see who is funding last-minute advertising blitzes until after the election, reducing accountability.
The tactic has grown explosively: spending by these groups is up nearly 35-fold since 2022, reshaping how campaigns are financed.
Both parties use the strategy, but the scale and speed raise concerns about transparency in campaign finance.
Background
Super PACs can raise unlimited money from corporations, unions and individuals but must disclose donors in regular FEC reports. Groups formed after the Oct. 15 filing deadline can spend freely for weeks without their donors appearing on the public record. The total spending by these 22 late-forming groups has already eclipsed comparable spending in the past two presidential elections.
Key Perspectives
Michael Kang (Northwestern Pritzker School of Law): says the practice is "almost entirely to avoid disclosure, even if just temporarily," and that "if the donors were known, then it would undercut their cause."
Saurav Ghosh (Campaign Legal Center): says "It's happening more often, and they're spending more money doing it because it works, and they're getting away with it." He calls the groups "a vehicle designed to emerge from nowhere and spend a bunch of money on an election" before voters can learn the donors' motivations.
Hilary Braseth (OpenSecrets): says a locally branded PAC "doesn't necessarily hide where the money comes from, but it fragments the picture," making it harder for voters to see the national organizations behind the spending.
What to Watch
The Dec. 3 deadline when several late-forming PACs must file their first regular donor reports, possibly revealing major contributors.
Whether the 2028 election cycle sees further growth in pop-up PACs or if Congress or the FEC move to close the disclosure gap.
The outcome of races where pop-up PACs have concentrated spending, such as Texas and Maine, to assess the tactic's effectiveness.
12 claims in this story checked against 1 source: 12 supported.
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SupportedPop-up super PACs had poured roughly $637 million into 2026 midterm races.US Top News and Analysis: “Together, they had reported roughly $637 million in independent expenditures by Oct. 29”
SupportedMost late-forming PACs spent before filing their first donor report.US Top News and Analysis: “almost all started spending before filing their first regular campaign finance report showing where their money came from.”
SupportedTwenty-two super PACs registered in the final 10 weeks before Election Day had each spent at least $1 million on congressional races, and together reported roughly $637 million in independent expenditures by Oct. 29.US Top News and Analysis: “Twenty-two super PACs that registered with the FEC during the final 10 weeks before Election Day have each spent at least $1 million on congressional races, according to CNBC's analysis. Together, they had reported roughly $637 million in independent expenditures by Oct. 29”
SupportedThe groups accounted for about one-sixth of independent spending in House and Senate races that election cycle.US Top News and Analysis: “about one-sixth of all independent spending reported in House and Senate races this election cycle.”
SupportedMichael Kang said, “The reason for this is almost entirely to avoid disclosure, even if just temporarily,” and, “Many times, if the donors were known, then it would undercut their cause.”US Top News and Analysis: “"The reason for this is almost entirely to avoid disclosure, even if just temporarily," said Michael Kang, a Northwestern Pritzker School of Law professor who studies campaign finance. "Many times, if the donors were known, then it would undercut their cause."”
SupportedSaurav Ghosh said, “It’s happening more often, and they’re spending more money doing it because it works, and they’re getting away with it.”US Top News and Analysis: ““It’s happening more often, and they’re spending more money doing it because it works, and they’re getting away with it,” said Saurav Ghosh, director of federal campaign finance reform at the Campaign Legal Center.”
SupportedHilary Braseth said a locally branded PAC “fragments the picture,” making the national organizations behind spending harder for voters to see.US Top News and Analysis: “"A locally branded PAC doesn't necessarily hide where the money comes from, but it fragments the picture. Instead of seeing one national organization spending tens of millions of dollars across the country, voters see a series of different groups operating race by race," said Hilary Braseth”
SupportedFederal law requires super PACs and political committees to report large independent expenditures within 24 or 48 hours, depending on how close the spending is to Election Day; donors are disclosed less frequently through periodic reports.US Top News and Analysis: “Federal law requires super PACs and political committees to report large independent expenditures within 24 or 48 hours depending on how close to Election Day the spending occurs, showing how much they spent and which candidates they supported or opposed. Their donors, however, are disclosed less frequently through periodic campaign finance reports.”
SupportedOur Heritage Matters registered on Oct. 15 after a key reporting deadline, and its first regular report identifying donors is not due until Dec. 3.US Top News and Analysis: “Because Our Heritage Matters formed after a key campaign finance reporting deadline on Oct. 15, its first regular report identifying its donors is not due until Dec. 3, a month after Election Day.”
SupportedAt the same point in the 2022 midterms, five comparable groups had spent about $18 million combined.US Top News and Analysis: “At the same point in the 2022 midterms, just five comparable groups had spent about $18 million combined, according to CNBC's analysis.”
SupportedNo Going Back PAC had spent roughly $242.2 million by Oct. 29, making it the largest spender among the late-forming groups.US Top News and Analysis: “By Thursday, No Going Back had spent roughly $242.2 million, according to FEC filings.”
SupportedElon Musk gave the Senate Leadership Fund $158 million in two contributions, and the fund transferred matching amounts to Texas PAC the day after each donation.US Top News and Analysis: “On Oct. 15, FEC filings showed Musk had given the SLF $158 million in two contributions, with the group transferring matching amounts to Texas PAC the day after each donation.”