Susan Pinker has this article in the WSJ with the above title, reviewing the research.
In the previous post, I noted my rare agreement with Jerry Brown that a marijuana industry with legitimacy and mass marketing would produce an increase in consumption that will diminish us as a nation. This is why. We are already suffering from a decline in the ambition and work ethic that made us a great nation in the first place. The last thing we need is a chemically induced steepening of our decline.
In the previous post, I noted my rare agreement with Jerry Brown that a marijuana industry with legitimacy and mass marketing would produce an increase in consumption that will diminish us as a nation. This is why. We are already suffering from a decline in the ambition and work ethic that made us a great nation in the first place. The last thing we need is a chemically induced steepening of our decline.

It'll take them forever to get off your lawn at that point. It's a little naive to think that our nations past was some pure collective of people free of any drugs or physical corruptions. Drug use was rampant through our countries history, and for a good time none of them were illegal.