If a President makes exaggerated and misleading statements in a forest and there is no one there to hear them, is the President lying? While philosophers might love to argue a question like this, it is clear that there are no practical implications that would make anyone conclude with certainty that there has been a lie.
On the other hand, if the President makes the same statements with a large audience who accept them and make decisions based on them, then any reasonable person would conclude that he was, in fact, lying. It all depends on whether the statements made by the President were exaggerated and misleading.
Congress acted on the administrations' statements about pre-war intelligence, and a war was started. If the statements were exaggerated and misleading, then the fact that the Democrats accepted them and made decisions based on them, makes the lies more obvious, not less so.
Let's look at it from a more basic perspective, shall we?
Suppose the President was driving a car filled with an equal number of Republicans and Democrats, and he decided that he really wanted to have all the windows rolled down. He could offer a rational explanation for why he wanted to roll down all the windows, and allow his passengers to debate the pros and cons before deciding if it was a good idea to roll down all the windows.
Or, instead of giving his passengers all of the information, the President could simply decide to fart - and everyone in the car, Republicans and Democrats alike, would respond by frantically rolling down all the windows! Mission accomplished, right? But suppose that the President, while rushing to roll down his own window, were to veer into the oncoming lane and force another car off the road, causing a fatal accident.
So who is responsible for the accident? The President, it now appears, is trying to argue that because the Democrats were actively rolling down their windows along with the Republicans, that they are all equally responsible for the accident!
However, the fact remains that the President was driving the car! The fact remains that the President chose to give the Democrats intelligence that, quite frankly, stunk! It got him what he wanted as quickly as he wanted it. However, the end result was a disaster, and now he is trying to blame the Democrats for the fact that they responded to the smell!