You will be surprised to know that American youth suffer from a debilitating lack of access to firearms. At least, that’s the contention advanced in a petition filed late last month by the National Rifle Association, which asked the U.S. Supreme Court to overturn a lower-court ruling that upholds a law banning federally licensed gun dealers from selling handguns to anyone younger than 21.

It’s worth keeping a few things in mind when contemplating the NRA’s latest effort to promote gun sales. First, every state in the union forbids the sale of alcohol to people under age 21. Second, as a 2013 report from the National Academy of Sciences states, behaviors and characteristics associated with adolescence are “positively correlated with increased risk for firearm violence.” In fact, according to research by Daniel Webster of Johns Hopkins University, the correlation is particularly acute between the ages of 18 and 20, when the homicide-offense rate peaks. (See chart.)

Anyone 18 and over can buy a long gun from a federally licensed dealer. Anyone 18 and over can buy a handgun from an unlicensed supplier (although a few states require residents to be 21). As we see it, restrictions on youthful gun ownership already seem pretty porous.

The NRA disagrees. “Given the number of laws enacted by the federal government, states, and localities in the years when a mistaken understanding of the Second Amendment held sway, one would have expected a major reconsideration of extant firearms laws to have occurred,” the group’s petition states. “It has not. Instead, jurisdictions have engaged in massive resistance to the clear import of those landmark decisions, and the lower federal courts, long out of the habit of taking the Second Amendment seriously, have largely facilitated the resistance.”

So there you have it. Given the court’s landmark 2008 decision creating an individual right to gun ownership, the NRA doesn’t understand why gun laws haven’t evaporated nationwide. The NRA’s problem isn’t “massive resistance”; it’s common sense and law. Even Justice Antonin Scalia, writing on the Second Amendment right to bear arms for a narrow 5-4 majority, noted, “Of course the right was not unlimited.”

In fact, gun rights in the U.S. have always been limited -- and in ways far more strict (and sensible) than what we see today. The reason for this is not hard to discern: Guns are lethal, and they are especially dangerous in the hands of young people, who sometimes lack the maturity and self-control to manage confrontations.

The Roberts Court has already liberalized gun laws far beyond the scope of any previous Supreme Court. Now would be a good time to stop. The court should reject the NRA’s petition.

To contact the Bloomberg View editorial board: view@bloomberg.net.