The Maori Party wants to ban smoking. I can see where they're coming from, given the havoc tobacco addiction wreaks among their community, but this is a step too far. You can justify banning smoking in offices and bars in order to defend the rights of people who don't choose to give themselves lung cancer. You can justify age limits on sale and larger and larger warnings on the grounds that people should know what they are getting into. And you can justify taxing the crap out of it to ensure that smokers pay the full social cost of their addiction. But actually banning what people do in their own homes, or outdoors when it won't affect anyone else, is grossly illiberal.
And OTOH, as DPF points out, cigarettes would almost certainly fail to gain approval from product safety authorities if they had been invented today. We only accept it because its already widespread. And many of the policy problems against prohibition (such as the risk of simply creating a black market) are consequences of this fact. Policywise, we have to work with the world we've got, a world where regulation of tobacco consistent with other goods we allow on the market simply will not work.