In his pitch-perfect address at Sunday’s prayer vigil in Newton, Conn., President Obama performed the two urgent duties that Friday’s tragedy demanded: He consoled the families of the victims, the rest of the shocked and suffering town and, indeed, the entire nation; and he declared, flatly, that after too many massacres of innocent people, something has to change. In fact, what he said was “we” have to change.

And we do. As Obama said, “What choice do we have? We can’t accept events like this as routine.” Only a sick and helpless society would, and we are neither of those.

We have to take steps appropriate to the ongoing carnage across the country, not just in Newtown, but in Aurora, Colo.; Tucson, Ariz.; Oak Creek, Wis.; Blacksburg, Va.; Littletown, Colo., and all the other American places where armed people – always men – commit mass murder. If this massacre of 20 innocent school children and six brave adults isn’t enough to shake the nation out of its complacency, then what is? Do we simply wait for the next mass murder, as there assuredly will be?

This problem is not exclusively about access to weapons that are designed to kill as many people as possible as quickly as possible – mental health and treatment for it are also wrapped up in these crimes. But access to assault weapons is plainly a critical issue. What today is the compelling counter-argument to controlling them?

That it won’t work all the time? Neither do laws against murder, but we don’t make that an excuse to drop such laws. It’s not the Second Amendment, since it allows appropriate controls over other weapons. And, in any case, all of our constitutional rights have their limits.

Absolutists will make that argument, anyway. It’s a too-familiar refrain when the country faces difficult choices. Confronted with millions of Americans lacking health care, or with the facts of climate change, the do-nothing crowd takes up the chant that, at its root, says, “You can’t do anything about that.” They say that we actually are helpless.

Some of that has already begun. Former Arkansas Gov. Mike Huckabee, a man who wanted to be president, insisted that this is a “heart issue” and that “laws don’t change this kind of thing.”

Even more predictably, Huckabee linked the shooting to his contention that “we’ve systematically removed God from our schools.” He asked: “Should we be so surprised that schools would become a place of carnage?”

But God hadn’t been removed from the Sikh Temple in Oak Creek, Wis., where a gunman killed five people and wounded four before taking his own life in August. God hasn’t been systematically removed from movie theaters, either, but that didn’t stop a gunman from entering one in Aurora, Colo., and murdering 12 people who came to see “The Dark Knight Rises.” God, presumably, hasn’t been driven out of the Bible Belt, which has seen its share of these tragedies.

It was a foolish comment, both wrong and unhelpful in the aftermath of an unspeakable crime. Atrocities like these demand serious comment from serious people, not boilerplate from former politicians who want nothing more than to advance a do-nothing political agenda.

The question is whether it is possible to craft tough legislation that respects the Second Amendment and doesn’t needlessly impinge on the legitimate rights of hunters and others to keep weapons. The question answers itself. No sportsman needs assault weapons. People may want assault weapons for all sorts of reasons, but in light of the bloodshed in Newtown and a dozen other places, it becomes necessary to draw a line.

We draw those lines regularly in this country. The right to free speech famously excludes the right to shout “Fire!” in a crowded theater. Freedom of the press is limited by libel laws and by laws protecting some young criminal suspects. The First Amendment offers no protection to those who traffic in child pornography.

But because of the American fascination with firearms and a powerful and amoral gun lobby, we are told such common-sense limits can’t apply to the weapons industry. That’s a lie, but that hasn’t stopped many people from believing it.

There come tipping points in history when even the doubters are forced to acknowledge hard realities. For climate change, it may have been Hurricane Sandy that finally convinced the resisters that we have to act. For too-easy access to guns, it may be what happened Friday at Sandy Hook Elementary School.

Let us hope it is, because if this kind of carnage doesn’t cause us to rethink our assumptions, then the bloodshed has hardly begun.