Remember John Edwards? Manlier then Hillary, whiter than Obama, but by some estimations more progressive than either? Not as progressive as Kucinich, of course, but Edwards is considered more electable - especially by NBC, which is trying to revoke Kucinich's invitation to a debate.
And apparently they'll be able to keep Kucinich out, so long as they keep the broadcast only to cable's MSNBC. Broadcast and cable TV fall under different rules.