Look, I think that what the Dems want/need for their election prospects are a body. They need to get someone, ANYONE from the Bush administration to leave in shame. This would give them the ability to attack Bush's "Restoring Honor and Dignity to the White House" comments that so angered the Democrats. It was an attack on Clinton that the Dems could not defend against, and it was lethal.
They are going after Rumsfeld specifically, with attacks on others (especially Rice) to follow. All they have to do is get one person to leave in disgrace, and then it is open season on Bush. Without that, they have nothing on which they can attack Bush without it looking political.
You are correct but it is just one of their little scams, they have a big bag of tricks.