Two economists set out to measure what happened when Republican fundraising emails vanished into spam folders last year. They found an answer, an estimated $117 million in lost donations, and a problem they could not get around.
They could see the cause only because private test results leaked to the press. Outside the email companies, nobody knows how the filters decide.
“We can’t read their minds,” Lars Powell of the University of Alabama told the New York Post.
The Researchers Could See the Problem Only Because of a Leak
Powell and Cameron Ellis of the University of Iowa posted their paper in July. It drew little attention until the Post reported on it Monday.
Their subject was WinRed and ActBlue, the online donation platforms that Republican and Democratic campaigns rely on. Using federal campaign finance records, they tracked first-time donors on each.
During a 78-day stretch that began June 30, 2025, Google‘s Gmail, Microsoft‘s Outlook and Yahoo sent emails with WinRed links to spam. Otherwise identical emails with ActBlue links went to the inbox, and first-time WinRed contributions dropped 75%.
An earlier Outlook-only episode, from February through April, cut them 83%. Microsoft declined to comment.
Combined, the researchers counted 142,126 missing first-time gifts. A new WinRed donor gave $827 on average over eight months, which puts the total value near $117 million.
How did they know when the filtering started and stopped? They relied on inbox tests run by Targeted Victory, a Republican consulting firm. The firm’s memo reached the Post in August 2025, showing Gmail branding WinRed-linked messages with a red warning that they “seem dangerous.”
Without that leak, the authors wrote, the mechanism would have stayed invisible. A narrow decision by a few providers about how to treat certain links moved millions of dollars, and no one outside those companies would have known why.
Google’s Answer Hasn’t Changed
A Google spokesperson told the Post that the study rests on “deeply flawed methodology” and that Gmail treats every sender the same regardless of party. The company also dismissed the $117 million as a theoretical estimate.
Owners of the stock of Google’s parent company, Alphabet, have heard this before. In December 2018, CEO Sundar Pichai told the House Judiciary Committee he ran Google without political bias. He brushed aside studies of skewed search results by citing problems with their methodology and sample sizes.
In 2019, Northwestern University researchers found that Google News “Top Stories” drew heavily from left-of-center outlets. Google replied that it had no insight into the researchers’ methodology.
In October 2022, the conservative Media Research Center reported that Google buried the campaign websites of 10 Republicans in 12 tight Senate races. Google told Fox News that the analysis was designed to mislead because it relied on search terms people rarely use. The group answered that the same method, applied to 36 toss-up House races, found no tilt against Republicans.
The response works because outsiders can’t check it. Google keeps the rules, the data and the test results to itself, then faults anyone who tries to reconstruct them.
NLPC Asked for That Disclosure in 2022 and 2023
NLPC has pressed Alphabet on this point at its annual meetings. In 2022, we asked the company to publish an itemized list of federal requests to remove content from Google and YouTube: who asked, what they wanted, and what Google did.
Alphabet’s board said no and pointed to its “Transparency Report.” Paul Chesser, director of NLPC’s Corporate Integrity Project, told fellow shareowners that the report did little more than tally requests from governments around the world.
In 2023, we asked for an examination of how Google and YouTube enforce their content rules. It would have covered the financial and reputational risks from claims of election interference and uneven treatment.
The evidence included a North Carolina State University study that found Gmail marked 59.3% more emails from conservative candidates as spam during the 2020 campaign. We also cited the RNC’s claim that more than 22 million of its emails went to spam in 2022.
The board assured investors that Alphabet had “safeguards in place” against “improper bias.” At the meeting, Chesser asked what, then, counts as “proper” bias?
Since then, YouTube has admitted to Congress that it banned creators under COVID and election rules it no longer enforces, and agreed to let them back.
Regulators, a Judge and a Workaround
Google can point to wins. The Federal Election Commission dismissed an RNC complaint in 2023, and a federal judge tossed the RNC’s lawsuit in 2024, though Axios reported that the judge called it a close case.
Those rulings came from bodies that, like Powell and Ellis, had to work from the outside.
Federal Trade Commission Chairman Andrew Ferguson took a different approach in August 2025. He warned Pichai in writing that running Gmail in a way designed to have partisan effects could break consumer protection law.
Within weeks, Google dropped SURBL, an outside blacklist service that flags suspect web addresses. Republican email delivery returned to normal, according to the paper.
This month Google launched a Gmail program that lets verified political committees with low complaint rates reach inboxes with fewer obstacles. Engadget observed that this is Google’s second attempt, after a 2022 pilot, to offer campaigns a detour rather than defend the filter itself.
The Record Goes Back to 2009
NLPC criticized Google in 2009 for backing a coalition that warned Congress about censorship tools while Google filtered search results in China. In 2016, Google told PragerU it doesn’t censor anyone, while YouTube kept 21 of the group’s videos restricted.
In 2019, a Google executive was recorded telling an undercover Project Veritas reporter that the company was working out how to prevent a repeat of the 2016 election.
The subject has shifted from search to video to email. Each time, the evidence came from outside researchers, leaked memos, a hidden camera or a congressional subpoena. None of it came from Google volunteering what it does.
