So what happens if people stop smoking (or more likely, start buying tobacco on street corners from drug dealers who realize that they can make more money selling cigarettes)?
Well, anyone with sense understands that, as you do. But hey, we're talking politicians here.
I guess they'd just find something else to tax -- red meat, alcohol, soda, candy ... you know, the stuff that people like but shouldn't indulge in according to our nanny state.