http://www.paperarticles.com/2008/09/us-presidential-race-erupts-into-spat.html

This site shows a newspaper article from September where John McCain complains that Obama is sexist because of comments he made about Sarah Palin. McCain is clearly trying using the gender of his running mate to his advantage by using it to attack his opponents. This is a powerful weapon because it seems that when Obama attacks Palin, the Republicans now will just accuse him of being sexist and Obama will look bad.