Hypothetical.
Make smoking illegal.
Once it is illegal, Tobacco Lords will start popping up everywhere. Gangs will sell tobacco in any form to make money, for what ever purpose they want. The street value of Tobacco will be determined by three factors, not two, Supply, Demand, and Risk. The higher the price goes, the more incentive there is for those who are willing to break the law to become involved, thus, it will become a War of Escalation. The War of Escalation wont be the only war, as those involved in the Tobacco Trade will fight to keep on trading. This includes local rival gangs and any form of government that gets involved. People will end up being killed as a result of the fighting. The more resistance they meet, the higher the price will go, the more incentive there will be to become involved in the Tobacco Trade and the more violence will ensue.
Tobacco will be used as an excuse by the Govt for more Govt Power. Families will be destroyed when mom or dad steps outside to have a smoke by either imprisoning the parent for the possession of illegal tobacco (controlled substance), or the child will be seized by the Govt claiming the child was endangered by a parent that was not completely obedient to the corrupt Govt. The integrity of the Govt will be comprimised by the incentives that tobacco offers. Thus, Govt will probably maintain the Tobacco Trade by growing and distributing tobacco themselves. Tobacco will be used to further increase our lead in the category of people in prison, per capita. Private Prisons will lobby against it. Some on the Govt payroll will get paid large ammts of money to look the other way. People wont stop smoking or chewing tobacco. Our govt wont listen to our cries to legalize it because they can make so much more money off of us by keeping it illegal. Higher taxes, more police, more people in prison, more violence, more families destroyed, more people dying, more excuses by the Govt to take what few rights we have away, more corrupt officials looking to line their own pockets, new types of Gangs, new types of Drug Deals, new types of Drug Testing for Employment, and so many more opportunities for those in power to take away from the people who dont smoke in order to punish them by keeping tobacco illegal. Then we discover that the consequences of making tobacco illegal are far far worse than keeping it legal.
Now, replace Tobacco with Marijurana. Does making Tobacco illegal sound like a good idea to anyone? Maybe instead of finding new things to make illegal, we should be thinking just as hard about making Marijuana Legal.