Sam Wang has an excellent blog called the Princeton Election Consortium. He has this very interesting take on the undecided voters out there:
Recent polls have “about 8% of voters saying that they are undecided. This figure suggests that movement in the race is still possible. For example, if all undecided voters decided to vote for McCain, the popular vote would be near-tied. But just how undecided are these voters, really?
In a recent study (news story), 129 residents of an Italian town were asked about their attitude toward a controversial expansion of a nearby U.S. military base. Researchers found that the opinions of 33 “undecideds” could be predicted a week in advance by a series of questions relevant to the issue. This result raises the possibility that decisions exist in an internal form before people can report them.
The work is reminiscent of neuroscience research by Antonio Damasio and colleagues, who found a way to measure the gap between hunch and recognition. People were asked to play a pretend gambling game in which they could choose cards from several decks. Without the participants’ knowledge, some of the decks were stacked against them. After losing repeatedly, they began to choose the more favorable decks but were unable to say why until after much further play.
So even when we claim to be undecided, we may have strong preferences that we cannot report to a questioner. This creates a major problem in interpreting the answers to opinion polls. There may not be many undecided voters out there at all.