President Barack Obama scratches his head as he speaks during a campaign event at the Bill Graham Civic Auditorium, Monday, Oct. 8, 2012, in San Francisco. (AP Photo/Carolyn Kaster)

Photo by: Carolyn Kaster

President Barack Obama scratches his head as he speaks during a campaign event at the Bill Graham Civic Auditorium, Monday, Oct. 8, 2012, in San Francisco. (AP Photo/Carolyn Kaster)