Prohibition has become known as a failure because there was still a vibrant underground alcohol trade, but it didn’t mean that everyone continued drinking at the same rate. It really did reduce alcohol consumption.
Mostly, after the brief sharp drop to around 30% of pre-Prohibition levels, just the much smaller (consumption at around 60-70% of pre-Prohibition levels) effects of the de facto tax collected by organized crime that prohibition imposed (“Changes in consumption were modest given the change in price. This suggests that legal deterrents had little effect on limiting consumption outside of their effect on price. Social pressure and respect for the law did not go far in reducing consumption during prohibition”.) [0]
And, both nicotine and alcohol have substantial regular taxes now, which serve the same purpose without fuelling organized crime, so prohibition would just redirect funds from the public coffers to criminal enterprise.
[0] https://www.nber.org/system/files/working_papers/w3675/w3675... , p. 8
I don’t find this argument convincing at all in the modern era. Synthetic drugs and even commercialized organic drugs are significantly more potent than anything that could be found a century ago.
Synthetic cannabinoids are vastly more addictive and dangerous than cannabis ever could be, for example. Synthetic drugs like MPDV are known to produce compulsive redosing even in people who could moderate their intake of traditional drugs like cocaine.
You can’t compare what’s available now to historic drugs.
Make the really hard stuff only available by prescription.
