But these politicians are also presiding over another morbid phenomenon, one that has crept on as American mass shootings have accumulated: the terrorizing of the American people, and the gradual closing-up of American public life.

First-graders are routinely faced with the question of what they ought to do if someone appears at their school intent on killing them. Moviegoers arriving at crowded premieres can expect to have their bags searched or to be monitored by armed guards. After passing through metal detectors, attendees at outdoor food festivals can anticipate surveillance by police on motorcycles or horseback, patrolling security barriers on the perimeters of the grounds. It isn’t that the safety precautions aren’t welcome, but rather that they come at a cost. They’re the scars left by prior shootings and a tangible memento mori. Death stalks grocery-store aisles and elementary school corridors, and it’s possible to remember a time when it didn’t.

But that time is ending. Each mass shooting forecloses the innocence of another place, another time, another activity. The majority of teenagers and their parents already worry about school shootings; as more settings become venues for mass violence, the fear will only spread, bringing its visible signals with it. Gun deaths belong in some sense to the lawmakers who are charged with the responsibility to care for the public but fail to meet their obligations, and so, too, does the darkening of American life, and all the liberty and happiness that terror cloaks in shadow.