I think it is much simpler than that.
They simply lie. Their main weapon is the lie and they do everything through the lie. I was listening to Hillary Clinton today about the murder of the Libyan ambassador and she was saying that the picture of the dead ambassador being dragged around represented Libyans trying to get him to the hospital. At the same time that she was lying through her teeth, CBS was reporting that the Libyan authorities had told the mob where the ambassador was hiding so they could go and kill him. In other words, this was a plot to get the ambassador murdered and it succeeded. Hillary knew this information. How could she possibly not know? Still she just lied as naturally as possible in her press conference trying to make people think something else. What really amazed me is how matter of factly she did this. These people do not know the difference between a lie and the truth as long as it suits their purpose. Overweighting polls is simply an extension of the lie. It is that simple.
Certainly, it may well be that simple.