An interesting column in the NY Times today (2008-01-10) by the head of the PEW Research Center, Andrew Kohut, one of the polls that predicted Obama over Clinton.
The polls get minimal response from poor, white citizens. Polls traditionally overestimate the support a black candidate will get from the white community because most of the respondants are better-educated, more affluent. Blacks are mistrusted by poorer whites. When voting takes place, the vote of these poorer whites, largely absent in poll-taking, becomes apparent.
Mr. Kohut points to a similar polling miscue in the Dinkins-Giuliani race in NY in 1989.
This column appeared in the OpEd section of the NY Times online today. Not sure if this link will work but if not, putting NY Times in google should start to get you there.
Getting It Wrong