The folks at Powerline make a very good point.

The Democrats appear to be putting all their eggs in the pre-war intelligence basket, but why? Certainly not because they actually believe it's a legitimate issue. Several investigations have already concluded that the Bush administration didn't manipulate pre-war intelligence, and the Democrats, from Bill Clinton on, made all the same claims about Saddam's weapons, etc., that the Bush administration did. Moreover, the whole idea that the administration would use Iraq's WMDs as a "pretext" for war is stupid. If the administration knew Saddam didn't have the weapons, then it also knew its "pretext" would be exposed as soon as the invasion was complete. No one would be dumb enough to go to war on the basis of a claim that was not only wrong, but would quickly be shown to be wrong. So the Democrats aren't acting in good faith, they're playing politics.

Further to this point, wouldn't you think it would have been easy enough to "plant" evidence of WMDs in Iraq for reporters to find?