Can you get smoking outlawed? If not, how much can you restrict it?
One way to get something more likely to be outlawed is to have an enemy of the United States get into it, the problem is that I doubt that we could end up with any of our enemies of the United States associated with Tobacco that wasn't in OTL.
In OTL, the world leaders that I associate with Tobacco are FDR, Churchill and Castro...
About the only way that springs to mind is to have someone like Saddam Hussein buy out one of the major cigarette manufacturers, but I'm not sure that does much more than shift the brands around...
Another option is to have a President who smoked be diagnosed with Lung Cancer and have *that* play out in the media. Say Reagan gets diagnosed with Terminal Lung Cancer in Spring of 1985? or GWB in 2005?