The Proteus Fund is a left-of-center “pass-through” funder and donor-advised fund provider. Since the Fund’s creation in 1995, Proteus has routed hundreds of millions of dollars from major grantmaking foundations and anonymous donors on the Left to activist groups targeting issues including legalizing same-sex marriage, reducing religious freedom to dissent

Population Connection is a left-leaning nonprofit advocacy group that supports global population control policies. The organization was founded in 1968 as Zero Population Growth by environmentalist and population control activist Paul Ehrlich directly following the publication of his controversial 1968 book, The Population Bomb. The organization affirms that population

People for the Ethical Treatment of Animals (PETA, sometimes styled PeTA) is one of the world’s largest, most aggressive, and most controversial animal liberation groups. The group has become notorious for aggressive campaigns against any and all human use of animals, even as it is dogged by allegations of hypocrisy

Naomi Klein is a prominent Canadian activist, syndicated columnist, and author of four books. She is a Writing Fellow at the Nation Institute and contributing editor for The Nation magazine. She has written articles for Harpers, The New York Times, The New Yorker, The Boston Globe, The Guardian,

The Gamaliel Foundation was originally founded in 1968 by left-wing activist Saul Alinsky, and re-oriented into a community organizing operation during the 1980s under the guidance of executive director Greg Galluzzo.

Dustin Aaron Moskovitz is an American Internet entrepreneur who co-founded Facebook with Mark Zuckerberg, Eduardo Saverin, Andrew McCollum and Chris Hughes. In 2008, he left Facebook to co-found Asana with Justin Rosenstein. 230

The William and Flora Hewlett Foundation (also known as the Hewlett Foundation) is a private foundation established in 1966 by Hewlett-Packard co-founder William R. Hewlett, his wife Flora, and his son Walter.

The Union of Concerned Scientists (UCS) is a Cambridge, Massachusetts-based activist group that uses science policy and climate change to advocate for left-of-center policies. As an activist organization, UCS began in the late 1960s with opposition to the Vietnam War and U.S. nuclear weapons testing, later coming to oppose peaceful

The U.S. Public Interest Research Group (US PIRG) is a left-of-center organization, founded by former presidential candidate Ralph Nader, that oversees a network of state-level advocacy groups also known as “PIRGs.” As the national organization for these independent state-based PIRGs, U.S. PIRG coordinates resources among its 47 state affiliates

Theodore Roosevelt Conservation Partnership (TRCP) promotes left-of-center conservationist and environmentalist policies. A membership organization of hunters and fishers, it is dedicated to promoting federal control of public lands and opposing expanded oil and gas production in the United States. The organization also has ties to organized labor and the

The Mangrove Foundation was a subsidiary of the Atlantic Philanthropies, a private foundation created in 1982 by Irish-American businessman Chuck Feeney. The Atlantic Philanthropies focused its advocacy on health, social, and politically left-of-center public policy causes in Australia, Bermuda, Ireland, South Africa, the United States, and Vietnam.

The Rockefeller Brothers Fund was created in 1940 as the charity for the five sons of John D. Rockefeller, Jr.:  John D., III; future U.S. Vice President Nelson; Laurance; Winthrop; and David. Two of these five men, Laurance and David, also established their own foundations, though David announced that the

For the related nonprofit, see Priorities USA Action (nonprofit) Priorities USA Action is a major Super PAC associated with supporting Democratic Party candidates and opposing Republican candidates. The organization was created in April 2011

The Pew Charitable Trusts is a public charity formed in 2003 from the merger of seven foundations created by the Pew family, which made its money in the oil business.  It operates the Pew Research Center as a subsidiary. Originally founded as the family foundation of conservative- and Republican-leaning

Pesticide Action Network North America (PANNA) is a California-based environmental advocacy and community organizing group. PANNA’s core objective is to oppose the production and use of many commercial pesticides and genetically engineered foods, as well as the agricultural corporations that employ these practices.

Note: This profile will be updated regularly as more information emerges on Arabella Advisors‘ acquisition by Sunflower Services. The New Venture Fund (NVF) is a 501(c)(3) funding and fiscal sponsorship nonprofit that makes grants to left-of-center advocacy and organizing projects and provides incubation serves

NEO Philanthropy (formerly Public Interest Projects) is a New York-based nonprofit that serves as a fiscal clearinghouse for left-of-center causes. The group serves as a vehicle for left-of-center foundations to pool resources, hosts donor-advised funds, and sponsors various advocacy projects.

James E. Hansen has been called the “father of climate change awareness.” Hansen, a former NASA scientist, is a climate change political activist. He has been arrested several times outside the White House while protesting mining and the Keystone XL pipeline.

The International Brotherhood of Teamsters (IBT), commonly shortened to Teamsters, is one of the nation’s largest private-sector labor unions. Principally representing employees in the trucking, railway, and airline industries, the Teamsters union has more than 1.2 million members.

The Environmental Working Group (EWG) is a major player in the environmentalist movement, focusing on issues related to regulating chemicals, promoting organic food, and opposing modern agricultural practices. EWG aggressively opposes the use of certain common plastics and farming techniques and has reportedly aligned with trial attorneys involved in major