http://en.wikipedia.org/wiki/MoveOn.org
Excerpt:
Financial contributors
According to an article in the Washington Post dated March 10, 2004:

"The Democratic 527 organizations have drawn support from some wealthy liberals determined to defeat Bush. They include financier George Soros who gave $1.46 million to MoveOn.org Voter Fund (in the form of matching funds to recruit additional small donors); Peter B. Lewis, chief executive of the Progressive Corp., who gave $500,000 to MoveOn.org Voter Fund; and Linda Pritzker, of the Hyatt hotel family, and her Sustainable World Corp., who gave $4 million to the joint fundraising committee."^[17]

MoveOn.org ceased receiving any donations to its 527 after the 2004 election, and closed the 527 permanently in 2008. MoveOn's primary source of funding is its members. MoveOn.org raised nearly 60 million dollars in 2004 from its members, with an average donation of $50.

[edit] Controversy