Lieberman was a decent debater. Your first assessment on wanting war veteran credentials may have had a point, but Kerry was boring as a debater, for starters, he had this awful habit of labeling specifics for groups of people he planned to serve. Bush and Lieberman have yet to demonstrate that kind of peeve. I’m not sure how much the whole Rathergate played out, but it certainly was over the top to begin with for me. I mean, isn’t saying that a guy served stateside enough to prove a point? Guess not.
I don’t think veteran status counts for much since the election of BJ Clinton, but in 2004 we were already in two wars and it may have meant something. I can only guess as to why Kerry was selected; he was as bad as McCain as a candidate.