Bill Bennett's pot prevarications: a former drug czar's dazed and confused defense of marijuana prohibition.

• Author: Sullum, Jacob
• Position: Going to Pot: Why the Rush to Legalize Marijuana Is Harming America - Book review

Going to Pot: Why the Rush to Legalize Marijuana Is Harming America, by William J. Bennett and Robert A. White, Center Street, 240 pages, $26

"With marijuana," declare William J. Bennett and Robert A. White in Going to Pot, their new prohibitionist screed, "we have inexplicably suspended all the normal rules of reasoning and knowledge." You can't say they didn't warn us.

The challenge for Bennett, a former drug czar and secretary of education who makes his living nowadays as a conservative pundit and talk radio host, and White, a New Jersey lawyer, is that most Americans support marijuana legalization, having discovered through direct and indirect experience that cannabis is not the menace portrayed in decades of anti-pot propaganda. To make the familiar seem threatening again, Bennett and White argue that marijuana is both more dangerous than it used to be, because it is more potent, and more dangerous than we used to think, because recent research has revealed "long-lasting and permanent serious health effects." The result is a rambling, repetitive, self-contradicting hodgepodge of scare stories, misleading comparisons, unsupportable generalizations, and decontextualized research results.

Bennett and White exaggerate the increase in marijuana's potency, comparing THC levels in today's strongest strains with those in barely psychoactive samples from the 1970s that were not much stronger than ditch weed. "That is a growth of a psychoactive ingredient from 3 to 4 percent a few decades ago to close to 40 percent," they write, taking the most extreme outliers from both ends. Still, there is no question that average THC levels have increased substantially as Americans have gotten better at growing marijuana. Consumers generally view that as an improvement, and it arguably makes pot smoking safer, since users can achieve the same effect while inhaling less smoke.

But from Bennett and White's perspective, better pot is unambiguously worse. "You cannot consider it the same substance when you look at the dramatic increase in potency," they write. "It is like comparing a twelve-ounce glass of beer with a twelve-ounce glass of 80 proof vodka; both contain alcohol, but they have vastly different effects on the body when consumed." How many people do you know who treat 12 ounces of vodka as equivalent to 12 ounces of beer? Drinkers tend to consume less of stronger products, and the same is true of pot smokers--a crucial point that Bennett and White never consider.

When it comes to assessing the evidence concerning marijuana's hazards, Bennett and White's approach is not exactly rigorous. They criticize evidence of marijuana's benefits as merely "anecdotal" yet intersperse their text with personal testimonials about its harms ("My son is now 27 years old and a hopeless heroin addict living on the streets ..."). They do Google searches on "marijuana" paired with various possible dangers, then present the alarming (and generally misleading) headlines that pop up as if they conclusively...