“I’m sorry,” said Representative Carolyn McCarthy, her voice breaking. “I’m having a really tough time.”

She’s the former nurse from Long Island who ran for Congress in 1996 as a crusader against gun violence after her husband and son were victims of a mass shooting on a commuter train. On Friday morning, McCarthy said, she began her day by giving an interview to a journalist who was writing a general story about “how victims feel when a tragedy happens.”

“And then 15 minutes later, a tragedy happens.”

McCarthy, whose husband died and son was critically wounded, is by now a practiced hand at speaking out when a deranged man with a lot of firepower runs amok. But the slaughter of 20 small children and seven adults in Connecticut left her choked up and speechless.

“I just don’t know what this country’s coming to. I don’t know who we are any more,” she said.

President Obama was overwhelmed as well, when he attempted to comfort the nation. It was his third such address in the wake of a soul-wrenching mass shooting. “They had their entire lives ahead of them,” he said, and he had trouble saying anything more.

It was, of course, a tragedy. Yet tragedies happen all the time. Terrible storms strike. Cars crash. Random violence occurs. As long as we’re human, we’ll never be invulnerable.

But when a gunman takes out little children in a bucolic Connecticut suburb, three days after a gunman shot up a mall in Oregon, in the same year as fatal mass shootings in Minneapolis, in Tulsa, in a Sikh temple in Wisconsin, in a theater in Colorado, a coffee bar in Seattle and a college in California — then we’re doing this to ourselves.

We know the story. The shooter is a man, usually a young man, often with a history of mental illness. Sometimes in a rage over a lost job, sometimes just completely unhinged. In the wake of the Newtown shootings, the air was full of experts discussing the importance of psychological counseling. “We need to look at what drives a crazy person to do these kind of actions,” said Representative Cathy McMorris Rodgers of Washington, one of the highest-ranking Republicans in the House.

Every country has a sizable contingent of mentally ill citizens. We’re the one that gives them the technological power to play god.

This is all about guns — access to guns and the ever-increasing firepower of guns. Over the past few years we’ve seen one shooting after another in which the killer was wielding weapons holding 30, 50, 100 bullets. I’m tired of hearing fellow citizens argue that you need that kind of firepower because it’s a pain to reload when you’re shooting clay pigeons. Or that the founding fathers specifically wanted to make sure Americans retained their right to carry rifles capable of mowing down dozens of people in a couple of minutes.

Recently the Michigan House of Representatives passed and sent to the governor a bill that, among other things, makes it easy for people to carry concealed weapons in schools. After the massacre at Sandy Hook Elementary School Friday, a spokesman for House Speaker Jase Bolger said that it might have meant “the difference between life and death for many innocent bystanders.” This is a popular theory of civic self-defense that discounts endless evidence that in a sudden crisis, civilians with guns either fail to respond or respond by firing at the wrong target.

It was perhaps the second-most awful remark on one of the worst days in American history, coming up behind Mike Huckabee’s asking that since prayer is banned from public schools, “should we be so surprised that schools would become a place of carnage?”

We will undoubtedly have arguments about whether tougher regulation on gun sales or extra bullet capacity would have made a difference in Connecticut. In a way it doesn’t matter. America needs to tackle gun violence because we need to redefine who we are. We have come to regard ourselves — and the world has come to regard us — as a country that’s so gun happy that the right to traffic freely in the most obscene quantities of weapons is regarded as far more precious than an American’s right to health care or a good education.

We have to make ourselves better. Otherwise, the story from Connecticut is too unspeakable to bear.

Nearly two years ago, after Representative Gabrielle Giffords was shot in the head in a mass shooting in Arizona, the White House sent up signals that Obama was preparing to do something. “I wouldn’t rule out that at some point the president talks about the issues surrounding gun violence,” said his press secretary at the time, Robert Gibbs.

On Friday, the president said: “We’re going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics.”

Time passes. And here we are.