I hate tobacco. But it’s legal. Outlawing its sale to someone born after x, but not one day before x doesn’t pass the smell test. If it’s legal for one, it’s legal for all. How is this different from, say, outlawing its sale to blacks?
One possible solution could be to prohibit the large scale domestic production, sale and importation of cigarettes into the country. Period This means that it is OK if a person lives in a climate area to grow your own tobacco for personal use. OK if a person wants to travel abroad and bring back a suitcase full of cigarettes. People would not be able to go to the local convenience store to buy cigarettes because they just wouldn’t be there. This would probable reduce the consumption of cigarettes by 99+ %. Would need to give the tobaccco farmers some lead time to change to another crop.