Perhaps DLC fellow traveler is the right term.
there are two gangs. One is the DLC/PPI gang, consisting of lapsed social-dems who have cut off their ties w/labor or civil rights, ambassadors to and from corporate america, and centrist pols. The second is centered around The American Prospect and Campaign for America's Future (Bob Borosage). I work for the second gang, tho I'm not quite a member in good standing. Greenberg is in the second. He collaborates with the first because they're in the same party and it's his business to help Dem candidates, whoever the hell they are. That's the skinny.