What sways independent voters? Pictures of themselves.
Check this out (via BoingBoing):

In a study conducted one week before the 2004 presidential election, a representative sample answered a series of survey questions about John Kerry and George Bush, including their vote intention.

The study consisted of three groups of respondents: one had their own photograph morphed into a picture of Bush, the second had their photograph morphed into a picture of Kerry, and the third was given un-morphed photographs of the two candidates.

The photographs of the respondents were acquired long before the study began; consequently none of the 200 respondents realized their own photographs had been morphed with the candidates.

The results demonstrated that respondents were significantly more likely to vote for the candidate with whom their face had been morphed (for both Bush and Kerry). This effect was stronger for people who did not have strong party affiliations (i.e., independent voters) than for strong partisans.

Sample pictures are at the site. If the candidate looks more like you, you're more likely to vote for him/her. I can see that happening in a race where the 2 candidates were essentially unknown to you. But with known quanitites like Bush/Kerry? A bit scary.