If you read Dreams from My Father, you'll discover that Obama is--or was--a serious smoker. Cigarettes appear as props in many of his memories. He's always stubbing them out or puffing on them to punctuate emotional points.
For the presidential campaign, he supposedly quit, but ABC's Jake Tapper recounts how he caught him backsliding (or smelling like he had), only to have the campaign categorically deny the candidate's cigarette habit. Now, however, Obama has 'fessed up, sort of. Not much of a scandal, if you ask me, but it does emphasize how public figures risk trouble if they try to carve out a backstage life that contradicts their public image. Once upon a time, Jackie Kennedy could be a chain smoker (and a fingernail-biter) and prevent anyone from catching her on film. And don't get me started on her glamorous husband's off-stage activities.