Yes, except that a government investigation by a bureaucracy into another bureaucracy is hardly going to do much for either party. The FBI and CIA already have jurisdiction spats - adding the one investigating the other (I'm assuming the FBI. . .I can't think of anything else that would work) would just bog down both agencies.
Furthermore, intelligence agencies are by their nature secret - and I don't think there's any group qualified to investigate them except themselves. Of course, Congress should have necessary information, but to gain it in the form of an open investigation would be divisive. It makes most people uncomfortable to have such secrecy, but IMO the only way for an intelligence service to work is for it to be able to work relatively unimpeeded. In terms of gathering information, as opposed to actions based on it - I'm comfortable as long as that information isn't about me

Basically, I'm trying to say that an investigation would reveal what is apparent enough. National security would not be jeopardized had Bush given a concrete example of something intelligence supposedly had. I.e. - "we have to invade Iraq because they have such and such weapon that we believe they are going to use"
That's enough for the people to build trust on. No jeopardizing details. However, the vagaries given as justification for the war were barely outright lies, or anything an investigation would turn up - if the government acted on poor intelligence, it really isn't unacceptable for them not to have mentioned all the details to the public. The simple fact that they had no details to release is damning enough.
An investigation would just clutter things, when the wrongdoing is likely in the interpretation of the intelligence, not the collection of it. I'm willing to accept that the administration had information the public did not, but had it been strong enough to justify the force used, it could have been at least partially released. Furthermore, I don't think the public has to have that information now. It's not really an issue of partisanship - that should be common sense.