Candidates are finding their images shaped by online forces beyond their control. Some, like Obamagirlspecial the Obama Girl online video show, have been helpful in forging a cool young image for Senator Barack Obama, reports Matt Bai, in  today’s Sunday New York Times Magazine.

Other "surprising" videos have not been as helpful, as this 1993 Rudolph Guiliani mayoral campaign ad featuring his former wife Donna Hanover with a stirring endorsement.  The clip (above) has been popular on YouTube.