Here's why: I don't like Lieberman very much. And I don't trust him very much either.
It looks like we have a real chance of taking the Senate. If the Democratic party had really alienated Lieberman, I still think he would have won CT. And if that happened, our chances of controlling the Senate would hinge on Lieberman's decision to caucus with Democrats. And I guarantee the Republicans would make him some attractive offers. I'm sure they will if Talent and Webb win. But as it stands, the Clintons and Gore, both of whom have such long working relationships with Lieberman, can pretty much call any decision of Lieberman's not to caucus with Democrats flat-out betrayal. Lieberman isn't an evil guy, and, because the Democrats didn't go balls-to-the-wall against him in CT, I don't think he can extort the party in good conscience now.
So I actually feel kind of relieved. Feel free to tell me why I'm wrong. I always enjoying getting a new perspective on things.
A couple more points on why I stand by my opinion:
1) If big-name Democrats had put a ton of effort into defeating Lieberman, I don't think we'd have the Webb victory that we do. This really came down to the absolute wire and I'm glad we put our people there instead of CT.
2) There's another reason Lieberman won't caucus with the GOP: he's still got some ambition. If he betrays the CT voters who put him in the office, then he's basically fucked for future races.
3) I just don't think Lamont would have won without unrealistically extensive campaigning from all the best Dems. They had bigger fish to fry in this race.
I'm sympathetic with those of you who dislike Lieberman, but I'm convinced the party decided correctly on this one. I'd rather have Lieberman and Webb (and Majority Leader Reid) than Lamont and Allen.