Everyone assumed Dewey would beat Truman. So much so, that some newspapers were printed in advance.
When Gary Hart ran for president, he dared the press to get him. This photo with Donna Rice did it.
Michael Dukakis thought this picture would help him. It was memorable, alright. It ended his career.
And then there is this picture. In the foreground is Barack Obama, standing in front of 75,000 people on May 18, 2008, in Portland, Oregon. Win or lose, my thought is that this picture will ultimately define the campaign.