Not for the first time, America appears in danger of coming apart at the seams. President Obama alluded to this at last week’s memorial service in Dallas for five police officers slain by an Army veteran said to be enraged over police killings of black civilians. “It’s as if the deepest fault lines of our democracy have suddenly been exposed, perhaps even widened,” the president said. “And although we know that such divisions are not new — though they have surely been worse in even the recent past — that offers us little comfort.”

One such previous time, of course, was during the Civil War, when the nation’s divisions over race devolved into bloodshed on a vast scale. In 1863, in the midst of that fiery trial, Abraham Lincoln wrote a letter responding to critics of the recently issued Emancipation Proclamation and of his conduct of the war. The Union victory he anticipated would prove conclusively, he wrote, that “among free men there can be no successful appeal from the ballot to the bullet.”

A hundred years later, in 1964, in another time of racial turmoil and on the brink of another ruinous war, Malcolm X spoke at a symposium in Cleveland sponsored by the Congress of Racial Equality. The topic was “The Negro Revolt, and Where Do We Go From Here?” In light of continuing oppression of blacks, he said, “If we don’t do something real soon, I think you’ll have to agree that we’re going to be forced either to use the ballot or the bullet.” Through all the tumult that followed during the ’60s, real change — albeit imperfect — came slowly and grudgingly through the political process, as the civil rights and the anti-war movements awakened the American conscience. 

What our time has in common with both those periods is, first of all, America’s Original Sin. The poisonous stain of slavery tainted our national life from the beginning and runs down even to the current time, sometimes subterranean and sometimes, as now, in the open. Race is not merely a fault line, but an ongoing American earthquake.

War is another tragedy in common. The Iraq and Afghanistan conflicts have involved far fewer Americans as combatants than the Civil War or Vietnam did, and the casualties have been correspondingly far lighter. But the war always comes home. It is not idle to wonder whether the militarization of the nation’s police forces, implicated in tragic encounters with black Americans around the country, has something to do with the flood of combat veterans who are now entering law enforcement. Another factor certainly could be the Pentagon’s ill-considered off-loading of surplus military equipment to local police departments. And, of course, the deranged killer in Dallas was so lethal in part because of the combat training he received in the Army. He returned from a tour of duty in Afghanistan, his family said, a completely different person. We suspect he is far from alone in that regard. All this is only to say that the wounds of war are not always visible, and the decision to wage it always has far-reaching consequences, many unanticipated.

And finally, what these times also have in common is people in public life who cynically exploited the country’s divisions for their own perverse ends. In the pre-Civil War era, John C. Calhoun of South Carolina, advocate of the doctrine of nullification, was a prime example; in the 1960s, George Wallace and Richard Nixon appealed to the nation’s basest instincts. Another such man is about to reach center stage this week at the Republican convention in Cleveland. His predecessors sowed the wind, and the country reaped the whirlwind. It could easily happen again.

Perhaps we are at another “ballot or bullet” moment in the national life. We hold with Lincoln here. Politics must be the way we settle our deep differences — racial, social, economic and ideological. Those who are thinking of sitting out the presidential election because they find both major party candidates distasteful or imperfect should think again. To do that would be to fail democracy’s stern test, one we have set for ourselves as a nation.