Smoking-related deaths will decline. If everyone is disallowed to smoke, than people will not have to go to rehab and spend thousands of dollars in an attempt to quit smoking. Also, other famous persons such as athletes will be forced to stop chewing tobacco, such as baseball players. Banning tobacco would ultimately be beneficial for society.
While it's obvious that the use of tobacco is a genuine problem for health in our world, it's never going to be feasible to ban its use entirely. All this will accomplish is creating a new class of criminals to overburden our hopelessly clogged criminal courts. The best we can do is reduce tobacco use through education and drug treatment center options.
No, banning the use of tobacco is not feasible. Legally, it is possible to ban tobacco. It could be counted as a categorized controlled substance, much like harder drugs. However, this will not stop nor prevent the use of tobacco, it will merely increase the burden already placed on law enforcement.
Because of it's addictive nature, people will still find ways to use it even if it is banned. Society will see a rise in incarceration rates for tobacco use, which will do nothing more than strain an already strained system. More prisons will need to be built, as more citizens become offenders.
Ideally, more treatment options would become available for those wishing to cease tobacco use.