“When guns are outlawed, only outlaws will have guns.” The National Rifle Association doesn’t really use that slogan anymore, but it came to mind last week as I considered a core tension in contemporary progressive thought: strong advocacy of gun control paired with increasing skepticism about law enforcement and incarceration.

In Philadelphia, for example, progressive District Attorney Larry Krasner has deprioritized gun possession charges altogether, holding that they fuel racial disparities and mass incarceration. At the same time, national Democrats are arguing more forcefully than ever for stricter gun laws. The last time this was actually successful, back in the 1990s, it was part of a seamless web of tough-on-crime politics — the assault-weapons ban was in a comprehensive crime bill that included hiring more police officers and provisions to build more prisons and make prison sentences longer.

Over the past 25 years, the left’s views on the merits of being “tough on crime” have shifted dramatically. But as the response to last week’s massacre at Robb Elementary School in Uvalde, Texas, shows, progressives remain deeply concerned about the dangers of widespread firearms ownership.

That is a reasonable judgment in the face of tens of thousands of lives lost. But to reduce the death toll from guns, progressives are going to need to move beyond a strategy of tweeting harder, fulminating more and placing blame on the financial clout of the now nearly defunct NRA. They will need to come to terms with the fact that reducing gun violence will require more policing and incarceration, not less.

Whoever wills the end also wills the means, Kant wrote. But contemporary progressives have shied away from the means — stopping people who break even minor rules, using their rule-breaking as a pretext for a search, and then punishing them if they are carrying a gun illegally — even while insisting on an increasingly expansive conception of their desired ends.

To be clear, quality-of-life policing would not have averted the Uvalde massacre. But neither would have background checks. Tighter rules on high-capacity magazines might have mitigated it, but then again they might not have — such rules are in place in New York state and didn’t prevent the mass shooting at a Buffalo supermarket earlier this month.

The point is that preventing these kinds of murders, in which a person with no prior criminal record obtains a weapon and then kills at random, requires imposing very heavy burdens on ordinary gun owners. The overwhelming majority of law-abiding gun purchasers, including buyers of terrifying semi-automatic weapons, do no harm.

Removing all of those weapons from the market is asking innocent people to make a considerable sacrifice. And it raises the question of how to enforce such a sweeping ban. A mandatory buy-back program would likely generate lots of compliance — among people who aren’t criminals. To get guns out of the hands of criminals would require intrusive policing and prosecutions on a scale that’s hard to imagine.

This is precisely the “Only outlaws will have guns” scenario that worries even non-fanatical gun owners. They acknowledge that, in principle, a gun-free America would be safer than the current gun-filled America. But they look at cities such as Philadelphia, where gun violence set a record in 2021, and with good reason don’t want to bring that model to the exurbs and small towns where they live.

The problem is that the small handguns that account for the vast majority of murders in America are easy to conceal. Police officers cannot tell by sight who is carrying them — they need to stop people and search them. This kind of intensive policing can reduce crime without violating constitutional rights, as academic studies of Operation Impact — in which the New York Police Department would flood high-crime areas with officers — have shown. The low-crime era in New York City continued for years after the end of “stop and frisk,” which was discriminatory and bred ill will.

That’s because officers continued to stop people — people committing crimes — and then frisk them. After the deaths of Michael Brown and George Floyd, progressive thinking turned to the idea that aggressive enforcement of laws against “low-level” or “non-violent” crimes such as shoplifting, turnstile-jumping or pot-smoking was a mistake. But while it is of course true that fare evasion is a minor crime, these low-level offenses can be a way to enforce gun laws.

And as liberals sporadically realize, when lots of people carry guns around, it’s very dangerous. In a city soaked with guns, gang disputes lead to bleed-outs rather than bruises. A bullet is much more likely than a knife to strike an innocent bystander. And a young man living in a dangerous neighborhood faces a basic cost-benefit calculus: Is the risk of arrest for carrying a weapon illegally greater than the risk of finding himself unarmed?

Vigorous enforcement of laws against illegal gun possession shifts this risk-reward calculus. First, it raises the risk of carrying. Second, by reducing the incidence of illegal carrying, it reduces the reward.

Years of steady application of this principle helped push many U.S. cities into a much safer equilibrium. Now that equilibrium has been disrupted by the dual shocks of COVID and reduced enforcement. Returning to a better equilibrium will be costly in terms of money and human suffering. But it will also have real benefits in terms of reduced gun violence.

Fulminating at congressional inaction in the face of spree killers may be satisfying and even necessary. But it is unlikely to persuade them to change the law. Continuing to insist on new rules while shying away from enforcing existing ones, meanwhile, burns credibility with conservative voters, who see a left that’s eager to penalize their hobby and reluctant to punish criminals.

Considerable progress against gun violence is politically and logistically feasible with more quality-of-life policing and vigorous prosecution of illegal gun possession — and the increased levels of incarceration both would require. If progressives want to make guns harder to get but don’t want to prosecute those who have guns illegally, then … it’s almost as if they’re inviting a future in which only outlaws will have guns.

Bloomberg Opinion columnist Matthew Yglesias is a co-founder of and former columnist for Vox. He is author of “One Billion Americans.” This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.