rather than a true conservative dem like Ben Nelson or Mark Pryor... it's odd I'll give it that.
Ben Nelson represents Nebraska. Mark Pryor represents Arkansas. A "liberal" Democrat would fail miserably in those Republican states, which is why the left supports them; they're better than nothing.
Actually, it's much simpler than that. Joe Lieberman goes out of his way to go on national TV and criticize other Democrats. He sucks up to the Bush whenever he can. He's a media whore. He undermines the party whenever he gets the chance.
Neither Ben Nelson or Mark Pryor criticize their party. They make our party stronger. Joe Lieberman makes the party weaker.
I wish people would understand this. It's really not a hard concept.