While I've had a very liberal view regarding drugs and certainly not bought into any campaign stories, I've also become much more respectful about their potential consequences in the past years from firsthand experience. It would be interesting to see more about how prevalent drug use is. I do think you underestimate the negative consequences they can have. Drugs like meth and cocaine don't just cause the users to think more clearly, it can also cause some big behavioral changes. For instance, it's not far-fetched that the economic crisis has been at least partly been caused by overconfidence from drug use: http://www.theguardian.com/business/shortcuts/2013/apr/15/co...