Actually, it won't matter much if it's actually true or not.
In terms of logic:
A proposition P is made. It has "historical boolean" value, which means that it either happened or didn't happen. Proposition P makes government G and one or more of their actions (G1, G2, ... GN) look bad and wrong.
Person A likes government G. He is not happy about what proposition P means, so he doesn't want to believe it. And guess what, he or she doesn't believe it until someone can prove without smallest doubt that its historical boolean really is "true", and even then it's possible that he or she will simply rationalize the government G's actions with some kind of illogicism that so much appeal to so many people.
Person B hates government G, and especially one of governments actions. So he or she is eager to accept the proposition P as "true", much regardless of it's actual, historical boolean value. So, he or she readily believes the proposition.
Person C is a rational being and doesn't "believe" in things, but rather only accepts proven facts as truth. This kind of people are nonexistant, obviously.
So, regardless of historical boolean value, this kind of news will have the following effect even before it's confirmed to be either true or false:
-people who want to believe it, will believe it to some degree
-people who don't want to believe it will deny it to some degree.
The degree of acceptance or denial varies from person to another, depending on their ability to think rationally and the strength of emotion that the matter invokes in them.
If the thing is found out to be historically true or false and proof of it is presented to everyone, there will still be few hardcore non-believers who will believe what they want. These people are the conspiracy theorists. Eventually, the historical truth will be the most common view, but until unambiguous proof is given on behalf or against the proposition, people will believe what they want to be.
Considering that there will be congressional elections in two days, I wouldn't be surprized if this news was released to further make the elections a question of Iraq war and stir the waters even more... It may not even be democrats' doings at all, it may be true or false and released by someone independend of both parties. What is certain is that if this kind of news spreads widely, it will in short notice strengthen the views of those who have a lot of "Person B" in them.
I myself would say that I consist some 60-80% of "Person C" and the rest in this matter would be "Person B". Which means that I am suspicious of this kind of news, but I wouldn't be too surprized if it proved to be true in the end.
I'll keep an eye on this, but most likely there won't be any trustworthy news about the subject until the elections are over and the results defined.