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

The Rockefeller Family Fund is the nonprofit organization supporting the philanthropy of the great-grandchildren of John D. Rockefeller and the grandchildren of John D. Rockefeller, Jr. The “cousins,” as Rockefeller Jr.’s grandchildren came to be known, were major supporters of left-wing counterculture causes as early as the 1960s.

Restaurant Opportunities Centers United (ROC or ROC-United) is one of the nation’s most prominent “worker centers,” labor-union-like organizations backed by union organizing know-how and left-of-center foundation funding. An outgrowth of a mutual-aid organization for the surviving unionized employees of the Windows on the World restaurant destroyed in the September 11th

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 center-left foundations to pool resources, hosts donor-advised funds, and sponsors various liberal projects.

Founded in 1909, the National Association for the Advancement of Colored People (NAACP) is the nation’s oldest civil rights organization. Over its 100+ year history The NAACP has grown exponentially to what is now a network of more than 2,200 affiliates covering all 50 states, the District of Columbia, Japan

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 over 1.2 million members.

Public Citizen, Inc. is a liberal 501(c)(4) lobbying and advocacy organization created by left-wing activist and former Green Party presidential candidate Ralph Nader.1 The organization supports a broad

Everytown for Gun Safety (better known by its short name, Everytown) is a New York-based lobbying group that advocates for gun control measures while opposing laws expanding firearms carry privileges. Michael Bloomberg, the former New York City mayor and founder and owner of global financial services and media company

Demos (formally Demos: A Network for Ideas and Action) is a nonprofit, New York City-based left-wing public policy advocacy group founded in 2000 that favors advocates a staunchly liberal agenda.1 Demos has close ties to the wing

Common Cause is a 501(c)(4) progressive advocacy group focusing on campaign finance law, so-called “fair redistricting,” and general liberal policy. Common Cause describes itself as “a nonpartisan, grassroots organization dedicated to restoring the core values of American democracy, reinventing an open, honest and accountable government capable of solving today’s challenges

For the 501(c)(3), see Color of Change Education Fund (Nonprofit) Color of Change is an online organizing organization created by the Obama administration’s former “green jobs czar” Van Jones and the former director of grassroots mobilization for MoveOn.org, James Rucker, in 2005.

Founded as a 501(c)(4) corporation and then a 501(c)(3) foundation in the late 1990s, Ballot Initiative Strategy Center (BISC) provides research and other support to progressive groups seeking to use state-level ballot referenda to change laws and constitutions, as well as using legal and activist tactics to block conservatives’

Americans United for Change is a left-of-center 501(c)(4) group characterized as a “dark money group” by the left-leaning Sunlight Foundation for its support of center-left causes and Democratic candidates.

350.org is a large environmentalist activist organization that has a presence in 188 countries. Focused on online campaigning, 350.org opposes new oil, gas, and coal exploration and development and calls for “[revoking] the “social license” of the fossil fuel industry and “[taking] money out of the companies that are heating

Also see Working America Education Fund (nonprofit) Working America is the “community affiliate” of the AFL-CIO, focusing on advocacy for and community organizing of non-union members. The group, founded in 2003, claims more than 3 million members, though as few as 15 percent may pay the $5 annual

Thomas Fahr “Tom” Steyer is an American hedge-fund billionaire turned climate-change activist, and major political donor to environmental causes and Democrats advocating an environmentalist agenda to fight global warming. Steyer made his fortune as the co-founder and senior managing partner of Farallon Capital Management, a hedge fund worth $30 billion.

Also see Tides Nexus The Tides Foundation is a major center-left grantmaking organization and a major pass-through funder to numerous left-leaning nonprofits. The San Francisco, California-based 501(c)(3) nonprofit was founded in 1976 by Drummond Pike, a professional political activist who has since retired from the organization, to funnel

The Service Employees International Union (SEIU) is one of America’s largest, most controversial, and most politically involved labor unions. The SEIU, which represents building services employees, nurses, other healthcare workers, and public employees, is noted for its close ties to the broader left-of-center movement, perhaps most notably the controversial now-defunct

Media Matters for America (MMfA) was established in 2004 by conservative-turned-liberal activist David Brock. MMfA was created as a 501(c)(3) tax-exempt, nonprofit organization. MMfA positions itself as a fact-checker, focusing on conservative media bias and inaccuracies. In practice, the organization frequently criticizes opinions of conservative commentators. In November 2023, MMfA was