However, tax filings reveal a who’s-who of wealthy conservative groups.

Among them are the Sarah Scaife Foundation, backed by the estate of right wing billionaire Richard Mellon Scaife; Donors Trust, which has gotten millions of dollars from a charity backed by conservative billionaire brothers Charles and David Koch and from the Richard and Helen DeVos Foundation—backed by the family of  U.S. Secretary of Education Betsy DeVos; and the State Policy Network, which has received funding from Donors Trust and is chaired by a vice president of the Lynde and Harry Bradley Foundation. Meredith Turney, a spokeswoman for the State Policy Network, declined to comment on fundraising or donations. Scaife, Donors Trust, Koch and DeVos representatives didn’t immediately return requests for comment.

In records obtained by the Milwaukee Journal Sentinel, the Bradley Foundation reported having given the Freedom Foundation $1.5 million in 2015 “to expand its union transparency & reform project,” including by opening a Portland, Oregon office. In Bradley Foundation records obtained by the non-profit Center for Media and Democracy, the foundation’s staff recommended providing the Freedom Foundation funds because West Coast union money “is used to subsidize the left’s national agenda and obstruct the mission and program interests of the Bradley Foundation and its allies.”

“They don’t want outsiders to hurt their freedom to earn a better life.”

Past Freedom Foundation literature seeks to turn workers against unions by highlighting six-figure salaries allegedly paid to union executives, as well as sending out postcards with images of a dingy hotel and a warning echoing an Eagles song: “You can sign up anytime you like but you can never leave!”

According to the group’s documents, targets for its new “insurgency” campaign include corrections officers and teachers, who will be out of school for the summer and thus “have no interaction with their union.” Because the Oregon chapter of the American Federation of State, County & Municipal Employees, or AFSCME, has been preparing members by “aggressively messaging” them, the anti-union group’s documents state, taking a more patient, less aggressive approach with those workers will help to “demonize” the union.

The Mackinac Center for Public Policy, a Michigan-based nonprofit that, like the Freedom Foundation, is a member of the State Policy Network and has received funding from Donors Trust, has launched a “My Pay, My Say” website that by Wednesday afternoon was informing public employees of their rights under the Supreme Court decision. The website offers an automated system for workers to generate letters to their unions opting out of paying fees or dues. Prior to Wednesday's ruling, the Americans for Prosperity Foundation, the 501(c)3 tied to the Koch-backed American for Prosperity, had already launched paid Facebook ads announcing that “Workers’ rights may soon be restored” and promoting the mypaymysay.com website.

AFSCME, which in 2015 privately estimated that half the workers it represents could be “on the fence” about whether to pay dues, said it’s trained 25,000 members who’ve helped conduct 800,000 face-to-face conversations with co-workers on the topic.

The American Federation of Teachers said that more than 500,000 of its members in the 10 states most affected by the ruling have recommitted to their union over the past six months, and that educators won’t be swayed by anti-union ads or canvassers funded by right-wing groups.

“When members find out who’s pulling the strings, they get pissed, because they don’t want outsiders to hurt their freedom to earn a better life,” AFT president Randi Weingarten said in an email. “We are confident that when members start getting harassed by these outside groups, they’ll be ready-not only to reject their assault, but to become more active in their union.”