Update

There's a lot of Edwards supporters, too, though not close to the number of Obama supporters. None of the other candidates look like they've got the needed 73 people, though Clinton might be close.

UPDATE: There's also a fair number of Biden supporters, probably not quite viable. But with uncommitted and other candidate support, they may reach viability. 

UPDATE 2: The Biden people just sent up a cheer, they may be viable.