First, a confession, I have become part of the marijuana economy. Well, kind of, I mean. I don’t partake myself. But last month I wialked into a head shop to buy what friends describe as the “iPhone of vape pens”, that is , a sleek little silver tube that allows one to vape marijuana without any visible smoke or vapor. It was a Christmas gift. The red-eyed young clerk who waited on me was like a refugee from a 1978 Cheech & Chong film. He kept calling me “man”. As I plunked down my credit card, I realized that I was experiencing, in a way, the past and future of marijuana’s mainstreaming , a legal moral and cultural sea change whose origins and development the author Emily Dufton ably chronicles a=in “Grass Roots”: The Rise and fall and Rise of Marijuana in America”.

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