Publishers
- Ble Solutions
- Borealis Philanthropy
- Brennan Center for Justice at New York University School of Law
- Bridgespan Group
- Bright Line Watch
- Brookings Institution
- Building Movement Project
- C.S. Fund
- California Community Foundation
- Campaign Finance Institute
- Campaign for the Civic Mission of Schools
- Carnegie Corporation of New York
- Cato Institute
- Cause & Social Influence
- Center for American Progress
- Center for Ballot Freedom
- Center for Community Change
- Center for Immigration Studies
- Center for Information and Research on Civic Learning and Engagement (CIRCLE)
- Center for International Policy
- Center For Judicial Engagement
- Center for Popular Democracy
- Center for Presidential Transition
- Center for Protest Law & Litigation
- Center for Strategic and International Studies
- Center for Voter Information (CVI)
- Center on Education and Workforce at Georgetown University
- Centre for the Future of Democracy
- Chicago Unbound
- CIVIC