The Illinois Democrat, who will formally launch his campaign Saturday, said his wife, Michelle (photo), persuaded him to quit.
"My wife wisely indicated that this is a potentially stressful situation, running for president," he said Tuesday. "She wanted to lay down a very clear marker that she wants me healthy."
The stakes are high for Obama not just because of the health hazards but because voters might be wary of a presidential candidate hooked on cigarettes. More.