According to a tweet today from Press Secretary Robert Gibbs, President Obama has quit smoking,
A president’s habits, be it “the vigorous life” of Teddy Roosevelt, not wearing a hat, like Jack Kennedy, or regarding fellatio from interns as “not sex,” as Bill Clinton did, have the power to change public attitudes and conduct for better or worse. This must have been an especially difficult time for Barack Obama to quit his long-time smoking habit, which typically is a response to stress. Despite perhaps the most stressful period in his life, the President did the right thing, and as good leaders must, to set an example.
We will never know for sure how much or how many, but his responsible conduct will undoubtedly change some behavior, and save some lives.
Ethics Alarms 
Good one. Knowledge is always relative to the context. When the context changes knowledge also changes. Men in public life strives to succeed setting personal example. It is an experiment with truth. Truth always and completely involves opposite values. Opposite values exist like day and night, complementary to each other, destruction and creation ad infinitum. Destroying bad habits elevates the good habits within. Once the bad habit is destroyed one should never look back. Anyone is capable of doing it, we are designed that way, including for those who have indulged in ‘not sex’ interpretations. The change effected by the leaders like President Carter’s born-again declaration, that shall be monitored and declared time to time, would bring a lot of solace to the people at large and a resolution to continue our fighting in life. I follow this principle for nearly 11 years that I have no paradox of life.
Opposite value of hunger is not eating but morality. Boxing-day is just a few hours ahead when one shall resolve to make everyday a boxing day.