I heard an alternative explanation to the "Bradley Effect" that in fact is not a racist one, and it makes sense to me. The likelihood that people may be silent or seem to support Obama because of social or union pressure, but will ultimately support John McCain due to the concern that if they discuss their decision with others they will be seen as racist. It seems to be completely plausible to me that this will undoubtedly be how many people react when they go to the polling place and they are not racist at all.