In the last five years, eight states have legalized recreational marijuana. To many, continued progress seems certain. But pot was on a similar trajectory forty years ago, only to encounter a fierce backlash.
Emily Dufton holds a PhD in American Studies from George Washington University. Her new book is "Grass Roots: The Rise and Fall and Rise of Marijuana in America." In it, she tells the remarkable story of marijuana's crooked path from acceptance to demonization and back again, and of the thousands of grassroots activists who made changing marijuana laws their life's work.