At her Senate confirmation hearing yesterday, Mike Riggs reports at The Daily Caller, acting DEA Administrator Michele Leonhart said marijuana legalization would be socially disastrous, and even talking about it is irresponsible, since criticizing prohibition only encourages drug use:

What worries me is that we have seen—after years of stabilization of drug use—a spike. I believe that spike is directly related to all the conversation we are now hearing about the legalization of drugs.

Leonhart presumably was referring to recent increases in drug use measured by the federal government's National Survey on Drug Use and Health. The share of Americans 12 and older reporting past-year use of illegal drugs (overwhelmingly marijuana) in this survey was 15.1 percent last year. That's barely more than the 14.9 percent rate found when the survey began in 2002, but it is nine-tenths of a percentage point more than the 2008 number (a 6 percent increase!). According to Leonhart, all the talk about legalizing pot provoked by California's Proposition 19, which qualified for the ballot in March 2010 and was defeated a couple of weeks ago, somehow drove up marijuana use in 2009. Forget about whether that's plausible; it's not even logically possible.

Even if it were true, so what? There is nothing inherently problematic about an increase in marijuana use. From an economic perspective, it indicates greater consumer satisfaction, and Leonhart offered no evidence of externalities big enough to outweigh that benefit. Roggs notes that her claims of disaster from softer drug policies are belied by the experiences of countries that have adopted them.

Declaring himself "a big fan of the DEA," Sen. Jeff Sessions (R-Ala.) dared Leonhart to take a brave stand by agreeing that repealing drug prohibition, her agency's raison d'etre, would be a big mistake. "Yes, I've said that, senator," she boldly replied. "You're absolutely correct [about] the social costs from drug abuse, especially from marijuana." She also promised that she will "continue to enforce the federal drug laws" in states that allow the medical use of marijuana—despite President Obama's promise to call off the DEA's medical marijuana raids and his attorney general's official policy of restraint in this area—because "I have seen what marijuana use has done to young people."

More on Leonhart here. The DEA's arguments against legalization have not gotten any stronger since I reviewed the agency's debating manual back in 1995.