Mickey Kaus thinks that the Democrats have impudently shifted the debate on Iraq from a topic they can win on ("Was the launching the war a good idea in 2003?") to one they may not be able to win ("Should we 'surge' or withdraw in 2007?"):
Debate A looks like a sure winner for Democrats--it's hard to see anything happening between now and 2008 that would convince a majority of voters that starting the war in the first place was a good idea. Debate B, on the other hand, looks much iffier, as the surge shows at least some signs of at least temporary success.
I think what Mickey fails to appreciate is how incapable your average senator is of saying "I was wrong." The problem that Democrats have is that most of them voted for the Iraq war in 2003. Any debate about whether that was a good idea, or not, is going to have to involve the Democrats explaining why they thought it was a good idea, then. The standard netroots complaint of a lying Bush makes experienced senators look like gullible chumps. I think the best possible honest case they could try to make is "It was a good idea based upon what we knew then, but Bush was so incompetent and screwed up so badly, we need to leave, now, before it gets any worse." Even then, I think your average senator - especially your average senator-with-presidential-aspirations - is going to have a hard time talking very proactively about why he (or she!) thought war was a good idea in 2003, but it is equally manifestly a bad idea now.
At the end, I think the Democrats have given up on what Kaus calls "Debate A" because they had basically the same position as the President, at the time. Which doesn't make for a very interesting debate.