Holy Joe's retirement closes the book, more or less, on a great question: was the decision by liberals to go all in on the primary challenge in 2006 a good idea?
I called it "a reasonable gamble by liberals gone bad" a while ago, but I think I was wrong.
Going back to the gamble...in 2006, Joe Lieberman was a very annoying Senator for many liberals, but he was not the most conservative Democrat in the Senate. He was, however, probably the Democratic Senator farthest to the right compared to his state, which made him a logical primary target, even if he wasn't so personally annoying. Alas for liberals, the primary wound up with probably the worst possible result. Had Lieberman won, he probably would have shrugged it off and continued on with his career; if he had been clobbered by Ned Lamont, he probably would have quit at that point. Instead, with Lamont edging him by 10,000 votes and everything else falling perfectly into place, Lieberman wound up returning to Washington as a party-defying independent.
As it worked out, however, I can't recall a single instance in which Joe Lieberman was the deciding vote against the Democrats. He was with Barack Obama on the stimulus, on health care, and on Dodd-Frank. He was a leader in the successful repeal of DADT, and the unsuccessful climate/energy bill. His voting record really didn't even shift very much. Against that is that he probably became even more annoying to liberals (here, I'll link again to Gail Collins's appreciation). And then there's whatever electoral value derived from his party-defying endorsement of John McCain in 2008, which I'd say was practically zero (and that's assuming he wouldn't have done it if he hadn't been challenged in 2006; if he would have done it anyway, and as a Democrat in good standing, the endorsement would have carried a bit more weight, for what it's worth).
And, now, his retirement. It seems to me very, very likely that had Lieberman won renomination unchallenged in 2006, he would now be running for another term and heading for renomination, at least. If 2012 turns out to be a fair-to-good year for Democrats, then as it is Connecticut will probably send a liberal Democrat to Congress, instead of returning Holy Joe for another term as a moderate.
Regular readers know that I'm usually pretty quick to point out the downside to ideological primary challenges. But I think liberals can be pretty happy with themselves on this one; even though things didn't work out how they wanted, they probably did wind up beating Joe Lieberman six years down the road, and with very little cost in the interim.