Young people who smoked marijuana in the 1960s were seen as part of the counterculture. Now the cannabis culture is mainstream. A 2022 survey sponsored by the National Institutes of Health found that 28.8% of Americans age 19 to 30 had used marijuana in the preceding 30 days—more than three times as many as smoked cigarettes. Among those 35 to 50, 17.3% had used weed in the previous month, versus 12.2% for cigarettes. While marijuana use remains a federal crime, 24 states have legalized it and another 14 permit it for medical purposes. Last week media outlets reported that the...