Activists, administrators, and national policymakers concerned about a supposed epidemic of rape on college campuses should stop trying so damn hard to regulate students' sex lives. Instead, their efforts would be better spent lobbying Congress to abolish a law that puts students at risk of sexual assault by encouraging them to consume alcohol recklessly: the National Minimum Drinking Age Act.

Just over thirty years ago, in response to public concerns about teen drinking and driving, Congress passed the National Minimum Drinking Age Act, which punished states for failing to raise the legal drinking age from 18 to 21 by taking away their highway funding if they refused. Within a few years, all 50 states and D.C. had fallen in line, making the U.S. one of only four countries with a drinking age higher than 18 (the others are Japan, South Korea, and Iceland).

Did the law decrease drunk driving? Many experts doubt it. Jeffrey Miron, a Harvard University economics professor and senior fellow at the Cato Institute, has argued that the law had "little or no life-saving effect." While a few states that adopted a stricter drinking age on their own saw limited, temporary success, the vast majority of states that prohibited teen drinking in response to federal bullying had little to show for it—other than the federal dollars they got to keep.

There is some evidence, however, that raising the drinking age might have actually worsened the teen binge-drinking problem. It's easy to imagine why that might be the case: if drinking any amount of alcohol is illegal for 18-year-olds, those who want to drink anyway have every incentive to down as much booze a quickly as possible, thus minimizing the amount of time they could be caught by the cops holding a beer in their hands.

The drinking age also creates a black market in alcohol consumption for college kids, most of whom are under 21 but drink anyway—just as their great-grandparents did during Prohibition. Teenage college students can't legally buy booze from the corner store or enjoy an afternoon or evening of casual drinking at the bar; instead, they have to seek out older students who are willing to give them alcohol. This means paying a visit to a friend-of-a-friend's basement, or diving head-first into the house party circuit and imbibing from a tub of mystery liquid. Fraternities, in particular, often play the role of beer distributors to the underage crowd.

These environment are manifestly less safe for teen drinkers than drinking at home or at a bar. But they are where teens must turn, thanks to NMDAA.

While there's no direct evidence that binge-drinking promotes rape—and indeed, contrary to what activists believe, campus rape rates are low and falling—alcohol is a factor in the vast majority of campus rape disputes. Students find themselves incapacitated, blackout drunk, away from their own beds, and separated from their friends—and that's when misunderstandings, regretted actions, and actual violence, occur.

Local actors might like to experiment with a different approach to alcohol, by either trying out a lowering drinking age (like the rest of the world), or something else. But colleges can't stop the cops from arresting teen drinkers. Neither can the states. That's because there is only one accepted policy on the books, and it's the law of the land: the National Minimum Drinking Age Act.

Congress should recognize that it's insane to force everybody to submit to an utterly failed restriction. Repealing the act might sound far-fetched, but in an era of incessant political bickering, it's something of an under-the-radar issue that would actually stand a chance of drawing bipartisan approval. Republicans who control Congress can strike a blow in favor of increased freedom and states' rights, and President Obama can show young voters that he does have their back. As Instapundit's Glenn Harlan Reynolds wrote after the November election, ending the federal drinking age is almost the perfect first move for the 114th U.S. Congress: "Easing pressure on states to raise their own drinking ages is consistent with GOP ideals. Obama hasn't been hot on lowering the drinking age, but it's hard to imagine him vetoing this."

If lawmakers want kids to drink responsibly, they need to legislate responsibly.