Jon Chait makes some pretty short work of his colleague Kirchick's dumb post on Joe Lieberman (if only other Planksters did the same more often...) but if anything Jon concedes too much. For example, agreeing that Lieberman "ran as a pro-war candidate."
Did he? I dunno. He ran ads saying things like "I'm staying because I want to help end the war in Iraq in a way that brings stability to the Mid-East and doesn't leave us even more vulnerable" and made statements on the trail about how "No one wants to end the war in Iraq more than I do." That kind of thing isn't literally inconsistent with his post-election position on Iraq, but I think it's clear that Lieberman was trying to use artful wording to present himself as much less of an Iraq hawk than he really is.
Certainly, Lieberman very much argued that Connecticut voters shouldn't view the election as a referendum on the war. After all, a referendum on the war would have meant Lieberman would lose the election since the war, enormously unpopular around the country by 2006, was even more unpopular in Connecticut. Instead, Lieberman tried to imply that he and Lamont were both for ending the war, and also argued that it would be foolish to base your support on a single issue. Today, Lieberman is arguing that John McCain's fanatical support for endless war in Iraq is a decisive reason to vote for him even though Lieberman nominally disagrees with McCain's positions on a whole host of other issues. That's a substantial change from the Lieberman who ran in 2006, on both what to think about the war and it's salience as an issue.