On Friday’s “PBS NewsHour,” New York Times columnist David Brooks said that the only way to have a meaningful impact on gun violence is to decrease the number of guns in the U.S., something countries like Australia have done. Brooks said, “[T]he more I look at it, and I’m not alone in this, the more you conclude that the simple problem is we have too many guns in America. There’s upwards of, some estimates, 350 million guns in this country. And so, when you get a lonely young man who’s detached and sociopathic, getting a gun for that person is...