Wikipedia
ActBlue is a United States political action committee established in June 2004 that enables anyone to raise money on the Internet for the Democratic Party candidates of their choice. It is independent of the Democratic Party itself and does not endorse individual candidates.
ActBlue has grown quickly to become a major fundraising tool for Democrats, with over 445 federal candidates and committees using the service during the 2014 election cycle. , ActBlue had raised more than US$1.1 billion for Democratic candidates and progressive organizations at various levels of politics, making it the largest single source of funds in United States politics. The organization is open to all registered Democratic campaigns, candidates and 501(c)(4) organizations. ActBlue is a not-for-profit organization. ActBlue officially incurs costs of 3.95% of the gross contribution, and those fees are passed on to campaigns.