Because for ONCE, the Left has used dirty and insulting tactics in a mainstream outlet to attack the far-right and the Bush administration.
I wish it weren't so, but most of us on the left are wimps--most on the right are wimps too, but they are wimps who are adept at groupthink and as such create the illusion of collective strength.
You don't have to have what you say backed up by facts, you just have to say it really, really loudly, over and over again. MoveOn.Org knows this.
Who gives a fuck if the General has betrayed us or not? Say he did and create your own reality!! This is what we are up against, a fanatical group of ideologues who can't distinguish truth from fiction.
So we have two choices: One, pursue a path of logic and use "facts" to back up our rhetoric until we are consumed by the propaganda of the right, or,
Two: Hit back with our own cheerleading and shift the political center to the left.
At that point, what used to be "left" is now moderate, because the "extremists" have come out in force and made the Democrats look even-handed.
The only problem? The Republicans in congress tacitly support their cheerleaders. The Dems don't yet.
Get on it. Call your representative and be illogical. They are vote whores. They will cave if you are strident enough.
Put reality out of your mind. We've got a goddamn war to fight.