Lieberman's certainly annoyed me about the Iraq war issue and because of plenty of Fox News Democrat moments, but actually where he annoyed me the most was when he was transparently full of shit about the Bankruptcy Bill. He voted against the final bill, but he was on the wrong side of the procedural vote which everyone knew was the only real way to stop the thing. He then proudly trumpeted his vote against it. That's the kind of thing Rick Santorum does.
If any credible primary challenger in Connectictut stepped forward they would get lots of support. Including, it seems, from Move On.