If you've only been paying attention to marijuana laws for a couple of decades, it can look like pot is on a bit of a high of its own.
State after state, including California and Oregon, has legalized marijuana for medical or personal use or both. This moment looked like a sure thing a couple of generations ago.
But then a backlash began against marijuana and other drugs.
Emily Dufton tracks the trajectory in Grass Roots: The Rise and Fall and Rise of Marijuana in America.
She joins us with both history lesson and cautionary tale.