Aspen Institute is a left-leaning, Washington, D.C.-headquartered think tank that focuses on convening senior-level professionals, hosting events, and driving dialogue across the business, communications, education, environment, health, criminal justice, philanthropy, and national security affairs sectors. 1

The Bill and Melinda Gates Foundation (Gates Foundation) was formed in 2000 by Microsoft founder Bill Gates and his wife, Melinda. Its total assets of nearly$55 billion (as of year-end 2021) make the Gates Foundation the largest private philanthropic foundation in the world.

American Lung Association is an advocacy organization whose primary mission since its founding in 1904 is advocacy for improving lung health, reducing the burden of lung cancer on patients, and running anti-tobacco campaigns.

The Threshold Foundation is a nonprofit and membership organization funding a variety of left-of-center causes. Based in Katonah, New York, the foundation’s president is Joan Briggs. 1 History and Causes Threshold Foundation was founded in 1981

The Wilderness Society is a left-of-center environmentalist group that primarily supports land conservation efforts, but also finances policy advocacy. Since its founding in 1935, the Society has helped protect nearly 112 million acres. 1 Since

The Alliance for Global Justice (AFGJ, sometimes styled AfGJ) is an organizing group that serves as a fiscal sponsor to numerous left-wing initiatives, among them Refuse Fascism,

The Sunlight Foundation was a government transparency advocacy group pushing for largely center-left government transparency measures.1 While the Sunlight Foundation claimed to be nonpartisan, its original national director, Zephyr Teachout, became a left-wing

New America, formerly the New America Foundation, is a left-of-center think tank in the United States. It focuses on a range of public policy issues, including national security studies, technology, asset building, health, gender, energy, education, and the economy. The think tank’s scholars and affiliated commentators include former and some

The Nature Conservancy (TNC) is the world’s largest nongovernmental conservation organization and ranked 20th on the 2018 Forbes list of the 100 largest U.S.-based charities. 1

The ClimateWorks Foundation is a left-of-center “pass-through” funding entity that distributes funds from donors to environmentalist advocacy groups around the world. Many of these nonprofits lobby for emissions taxes, restricting coal use, international climate treaties with strict enforcement mechanisms, and diminishing the use of cars.

Center for Social Inclusion (CSI) is a left-of-center social justice advocacy group that advocates for centering racial identity politics in policy activism. In 2017, the group merged with the left-of-center group Race Forward, which has a similar mission focused on race and identity, though both groups still submit separate tax

The American Constitution Society for Law and Policy (ACS) is a left-of-center legal activist group that aims to frame the United States Constitution as a document whose meaning shifts based on historical and political circumstances and that lawmakers should apply its articles and amendments accordingly. To advance this view, often

The Alliance for Justice (AFJ) is a left-of-center legal policy coalition composed of over 100 organizations. The group is best known for the Judicial Selection Project, which seeks to promote left-wing and Democratic-appointed judges while defeating conservative and Republican-appointed judges.

RepresentUs, founded in 2012, is a legally “nonpartisan” organization focused on reducing what it claims are the negative effects of campaign funding in American politics.1 The organization promotes proposed legislation that aims to increase certain campaign

The United Automobile, Aerospace and Agricultural Implement Workers of America International Union—also known as the United Automobile Workers (UAW)–is a labor union mainly comprised of American automobile manufacturing employees but that also includes unionized casino and higher education workers.

The Turner Foundation is a grantmaking nonprofit associated with the family of billionaire media executive Ted Turner. The Foundation primarily supports environmental conservation efforts, but also contributes to left-of-center environmental advocacy groups. Among the Foundation’s initial goals was “developing practices and policies to curb population growth rates,” a long-running

The Susan Thompson Buffett Foundation (STBF) is one of the charitable entities associated with billionaire Berkshire Hathaway investor Warren Buffett, who funds the Foundation. Founded in 1964 as the Buffett Foundation, STBF was later renamed for Warren’s late first wife Susan, whose estate granted the Foundation over $2 billion.

The Surdna Foundation is an advocacy and endowment management foundation1 funded by a contribution from capitalist businessman turned U.S. Representative John Andrus (R-N.Y.) in 1917. The Foundation has moved away from its

Rock the Vote is a left-progressive-aligned organization in the United States whose stated mission is to engage and “build the political power of young people.” The group claims to be nonpartisan,1 but has produced videos

ProPublica is an investigative journalist organization which publishes reports on perceived and actual abuses of power by governments, businesses, and other entities. 1 Its database of 9.6 million tax filing 990 documents for non-profits is used frequently by