>Interestingly, the reason we uncover such striking misperceptions does not appear to be that politicians are reluctant to admit a belief that public opinion is not on their side – many do. Rather, it seems that the reality of where the public stands on these issues has such a weak influence on politicians’ perceptions of public opinion that two candidates coming to judgments about the same constituents largely fail to have much more in common than would two candidates picked entirely at random
Basically, it is not that politicians intentionally mis-believe what their constituents support (willful ignorance, etc), the problem is that politicians are a poor representation of their constituents in general.
I've long maintained congress would be much more representative if eligible citizens were randomly selected for 1 congressional term, like jurors are in juries.