Another school shooting, another debate over gun control. An overwhelming majority of Americans want stricter gun laws, but Congress is unlikely to ban assault rifles outright, and some of the president's proposals -- a ban on "bump stocks," for example -- have unclear paths to success.
But there is another approach that would be constitutional and well supported by historical precedent. It might even help reduce the budget deficit that Republicans just sent skyrocketing. Of course, Washington is showing no signs of even considering it.
During Prohibition in the 1920s, organized crime took control of much of the market in illegal booze. Many of these criminals, as well as run-of-the-mill bank robbers and other miscreants, began arming themselves. While handguns proved useful, many opted for more dangerous weaponry: sawed-off shotguns, submachine guns like the "Tommy" gun, and full-fledged machine guns.
Gangsters like Al Capone put the weapons to use, shocking the nation with increasingly brazen shootings like the infamous St. Valentine's Day Massacre. Capone's gang mowed down seven members of Bugsy Moran's gang in a garage.
In general, though, the body counts rarely exceeded one or two unfortunate victims. Still, the steady pace of the incidents stoked widespread calls for action. In 1926, the New York Times, chronicling the carnage, observed: "America's criminals have turned the deadliest weapons of modern warfare against society."
It noted, in a rather eerie parallel to our own debate, that acquiring a machine gun was far too easy. "Any one who has the price can buy a machine gun or a hundred machine guns without hindrance. He is not required to show a certificate of good character to explain what he wants with such a weapon." The newspaper also took issue with the ability of the mentally ill to easily acquire machine guns.
As the deaths piled up, innocent bystanders got caught in the crossfire. In one especially notorious incident that took place in Manhattan in 1931, gangsters wielding machine guns wounded five children, killing one, during a failed attack on a rival.
Despite enormous public pressure, Congress did little more than pass a bill in 1927 imposing a prohibition on sending concealable weapons by government mail. Criminals circumvented it with ease.
The tide began to turn as the Great Depression worsened, and machine-gun toting criminals like John Dillinger became increasingly infamous. Newly elected President Franklin Roosevelt directed his new attorney general, Homer Cummings, to do something.
Cummings was an immensely capable, scrupulous man. After criminals gunned down a member of his own Justice Department and other law enforcement officers in the spring of 1933, he framed the problem as nothing less than "a challenge to American civilization." For Cummings, this was a war for the soul of the country. "We have got to win that war," he observed. "We shall."
But how? Many reformers wanted an outright ban on machine guns, silencers, sawed-off shotguns, and other weapons in the gangster arsenal. But Cummings knew that could easily invite a constitutional challenge.
So Cummings looked to another piece of federal legislation for inspiration: the Harrison Narcotics Tax Act of 1914, which imposed taxes on the production, distribution, and sale of opiates. Understanding full well that the power to tax was the power to destroy, Cummings proposed that Congress impose a $200 transfer tax each time someone bought or sold a machine gun -- or approximately $3,700 in today's money.
Thanks to this tax, the National Firearms Act of 1934 effectively doubled the cost of purchasing a machine gun, though the act made no provision for inflation: The tax remains at $200. But it also required that anyone who already had a machine gun to register it and pay the tax, too. Not surprisingly, most gangsters didn't want to detail their arsenals to the IRS. When police inevitably caught them with unregistered weapons, they would get charged with tax evasion and earn a prison bid -- even if it was impossible to prove they had committed any crimes with the weapon.
As gun control historian Adam Winkler has observed, this strategy was akin to the one used by the feds to take down Capone: tax evasion charges. And like that strategy, the gun tax worked. The popularity of these weapons effectively collapsed.
None of this amounted to a ban on machine guns: It was still possible to buy them even if almost no one did. And that's the lesson for today. If Congress is leery about trampling on gun rights but wants to do something about assault rifles, perhaps they should take some inspiration from Homer Cummings. Such a tax on assault rifles would be paid in cash or its equivalent (no credit cards allowed). In other words, if you just can't live without an assault rifle, then go ahead and buy one. But it will cost you dearly.
Would such a tax prevent mass shootings entirely? Of course not. But it would put assault rifles out of the reach of many disturbed individuals, and likely lead to the same precipitous drop in their popularity that hit machine guns after the 1934 law. That realization may help explain why a handful of cities and states have instituted modest taxes on both guns and bullets in recent years.
But these are baby steps compared to what Cummings proposed: a 100 percent tax. That scale would have a far greater consequence, one commensurate with the dangers posed by this particular class of weapons.
It would also generate considerably more revenue. But rest assured, there are plenty of deserving recipients of that money: the growing numbers of families who have lost loved ones to the AR-15 and its ilk.
Commentary by Stephen Mihm. Mihm, an associate professor of history at the University of Georgia, is a contributor to Bloomberg View.
Michael R. Bloomberg, founder of Bloomberg LP, which operates Bloomberg View, serves as a member of Everytown for Gun Safety's advisory board and is a donor to the group. Everytown for Gun Safety advocates for universal background checks and other gun control measures.