In May, a group called Accountable Tech, which calls itself a “small nonprofit taking on Big Tech companies,” organized a corporate boycott to protest Elon Musk’s bid to buy Twitter. In the midwest, a group called Opportunity Wisconsin, which bills itself as a “coalition of Wisconsin residents,” ran a deluge of TV ads slamming Republican senator Ron Johnson for his tax policies. And in Arizona, an organization of “grassroots racial justice” activists called Just Democracy released a video blasting Democratic senator Kyrsten Sinema for failing to support the Biden administration’s legislative agenda.

None of these groups actually exist. They are all registered trade names for the North Fund, a shape-shifting nonprofit group that uses aliases to push an array of left-wing causes from a shell office in Washington, D.C., according to corporate records.

Political watchdogs say the fund, which isn’t required to disclose the donors behind its $66 million budget, is gearing up to be one of the most consequential dark-money players of the midterm elections. And while “astroturf” groups are nothing new in politics, critics say the North Fund is part of a new breed—moving away from specific policy advocacy and delving into electoral politics.

“North Fund has said screw it,” said Hayden Ludwig, a senior investigator with the Capital Research Center. “They’ve just decided to be as partisan as they can.”

“Their money has been pretty much exclusively focused on Senate races, on ballot initiatives, and a few things kind of related to that,” Ludwig added. “The general theme there is cementing permanent Democratic majorities in Congress.”

The North Fund, which was founded in 2018, is helmed by a handful of Democratic operatives, including former Clinton aide Jim Gerstein. It operates under at least eight trade names, according to D.C. corporate records, including “51 for 51,” a group pushing for statehood for the heavily Democratic District of Columbia, and the “Voting Rights Lab Action,” which advocates for voting policy reforms favorable to Democrats.

Under the guise of “Opportunity Wisconsin,” the group has poured $4 million into negative TV advertising against Johnson, making it one of the top-spending outside groups in the state. Through another alias, the “Democracy Docket Action Fund,” the nonprofit has helped finance state-level redistricting lawsuits that favor Democrats across the country. And the “Accountable Tech” boycott campaign, which seeks to pressure Twitter to restrict speech from conservative outlets and Republican politicians, has received international news coverage.