MoveOn.org, the influential liberal organization founded during the impeachment of former President Bill Clinton, has never endorsed a presidential candidate. Until now. The Nation's Ari Melber reports that Sen. Barack Obama received 70 percent of the votes of MoveOn members during a vote conducted online, topping the 66 percent supermajority the group required in order to deliver its endorsement.

The actual effect political endorsements generally have on races is by no means a settled question, but the MoveOn nod could mean a lot for Obama as we head into Super Tuesday. MoveOn claims to have 1.7 million members in the Super Tuesday states alone, including more than 500,000 members just in California. That's about 10 percent of primary voters there. The group plans to start working on Obama's behalf "immediately," Melber says.