Cinemas like the one in Colorado where the shooting took place last week are closely regulated in virtually every respect but one.

Federal law requires large theaters to have wheelchair seating, ramps as well as stairs, and bathrooms that are accessible to the disabled. Fire codes limit audience size. Emergency fire exits must be illuminated.

We have a ratings system to protect children from nudity or offensive language. Indeed, on that horrific night in the theater last week, only one major element wasn’t regulated: the guns and ammunition used to massacre viewers.

As a nation, we regulate fire exits, but not 100-round magazines. We shield youngsters in cinemas from violence — but only if it’s on the screen.

Almost a week after the cinema shooting, we can also be sure what won’t happen: serious gun control. Both President Obama and Mitt Romney have supported a ban on assault weapons in the past, but both seem to have backed off for an obvious reason: the public has become pro-gun.

Since 1959, Gallup has asked Americans if they favor banning handguns. When the polling started, 60 percent said yes; the latest poll showed support from a new low of 26 percent.

The latest poll also found that, for the first time, a majority of Americans, 53 percent, opposed a ban on assault rifles.
Indeed, the immediate reaction to the Colorado shooting was a scramble to buy guns. The Denver Post reported a roughly 40 percent jump in background checks to purchase firearms.
“It’s been insane,” a gun store employee told the paper.
Quite.

Yet if traditional efforts at gun control are at a political dead end, there should still be room for a public health effort to mitigate their harm.

Take auto safety, one of the great successes of public health. Many car accidents involve unlawful behavior such as speeding or driving while intoxicated. We prosecute those offenders, but, for decades, we’ve also taken a broader public health approach. We’ve required seat belts and air bags, we’ve created graduated licenses for young drivers, and we have engineered roads and intersections so that accidents are less lethal.

The upshot is that the traffic fatality rate in the United States has fallen to a record low. Seat belts alone save more than 12,000 lives a year, according to the National Highway Traffic Safety Administration.

So if we can make cars safer, without banning them, then why not try to do the same with guns?

Look, I know this isn’t sexy. It certainly isn’t as satisfying to gun opponents as a ban on some kinds of firearms. But this approach might actually save thousands of lives.

Yes, the National Rifle Association will rant. But N.R.A. members are much more reasonable than their organization. There’s room for progress if politicians will show leadership. Hello, President Obama?

A recent survey found that more than 70 percent of N.R.A. members approve of criminal background checks for would-be gun owners. That suggests broad backing for one of the most crucial steps: a universal background check for all gun buyers, even when buying from private citizens. I’d also like to see us adopt Canada’s requirement that gun buyers have the support of two people vouching for them.

Other obvious steps include restricting high capacity magazines and limiting gun purchases to one a month. Making serial numbers more difficult to erase would help. And bravo to California for trying to require that new handguns imprint a microstamp on each bullet so that it can be traced back to the gun that fired it.
We should also finance research to design safer firearms. Many accidents would be averted if a gun always indicated if a round were in the chamber. And there should be ways to employ biometrics or a PIN so that a stolen gun would be unusable.

David Hemenway of the Harvard School of Public Health has written an excellent book about public health approaches to firearms. But he argues that we need changes not just in laws but also in social mores — just as we’ve stigmatized drunken driving. Not to mention other kinds of irresponsibility.

“Where I see social norms changing is dog poop,” Hemenway said in an interview. “You’re not allowed to let your city dog run loose now, and you have to pick up your dog poop.” He muses: What if people felt as responsible for their guns as for their dogs? For starters, one result might be more people buying gun safes or trigger locks.

The bottom line is that to promote public health and safety, we regulate everything from theater fire exits to toy guns (that’s why they have orange tips). And if we impose rules on toy guns to make them safer, shouldn’t we do the same with real ones?