The war has already been debated. It has already taken place. Nothing anybody can do or say will undo it now. It is the aftermath, at this point, that is important, not the rationale behind the war.
Let's say the Left is totally successful here. They manage to stoke public outrage. The Tories and Labour are voted out. Every Republican in America is either tarred and feathered in the media or they fall on their swords.
What then? The problem of 'Iraq- the Aftermath' is still there. We can still not simply pull up stakes and leave. We must still stay in the country and make the ole democracy thing work. Can the Left do this better than the Right? Personally, I think they would make a hash out of it and the world would be an even more dangerous place than it was before we got started.
Saddam was an evil f**ker. He had to go. That whole nest of snakes over there is going to have to be dragged out into the light and have their heads lopped off. The whole region needs to be reordered. I know some people would prefer to not do this for a variety of reasons, but I'm more of a hands-on kind of guy when it comes to some problems. Wishful thinking won't get rid of a schoolyard bully and appeasement won't make this world a safer place.
That's just me though. I'm glad Saddam's gone. That's my bottom line. If the President were to ask me for a list of other despots to topple- I could provide him with one as long as my arm and I wouldn't sweat the finer points of the international legality for taking each one down...