Last Dec. 14, a troubled 20-year-old youth shot and killed 20 children and six adults before he fatally shot himself at an elementary school in Newtown, Conn. The anniversary of this tragedy is itself a tragedy — of nothing learned.

In America, where the Second Amendment is placed by a hard-core minority above all other rights, mass shootings have unsurprisingly become regular affronts to domestic tranquility. But coming just before the Christmas season, this massacre of the innocents made a special claim on the nation’s conscience.

If the needless deaths of children and of adults who loved them could not move Americans to pity and reflection, then surely nothing would. For a few months afterward, it looked as if some meaning would rise from the meaningless slaughter. It appeared a do-nothing Congress might rouse itself to pass some modest controls on guns that struck a balance between the legitimate rights of gun owners and other Americans.

Small miracles fed hope: The Senate considered a bipartisan bill that would have expanded background checks for gun purchases. But by April, the Senate rejected the bill. The stale arguments and old prejudices prevailed, as usual.

Now the school is demolished, recordings of 911 calls bear new witness to the horror of that day, and Newtown’s residents are trying to put their lives back together. If only America’s leaders could honor them by doing the same for the nation. Instead, the lesson goes unheeded.

First Published December 14, 2013, 5:00 a.m.