Jacqueline Kennedy Onassis (R) and Lady Bird Johnson (2ndL), watch as US Vice President Lyndon Johnson (C) is administered the oath of office on a plane by Federal Judge Sarah Hughes (L) as he assumed the presidency of the US following the assassination of President John F. Kennedy in Dallas, Texas. (CECIL STOUGHTON/AP)

Most of us who were alive 51 years ago remember exactly what we were doing the moment we heard that President John F. Kennedy had been shot. That day in Dallas significantly changed my perspective on the presidency and American institutions.

I had just returned to my desk at the then-U.S. Civil Service Commission when I noticed that Shirley, our office secretary, was crying. She told me why. Nothing could have prepared us for that weekend in November 1963.

How do you get your head around the news that the president of the United States has been assassinated? Killed in broad daylight on a Dallas street. A president we looked up to, the titular head of an almost mystical family who was leading us into a New Frontier. Gone. Without any warning, gone.

That afternoon, sitting in front of a TV screen and holding my firstborn, 18-month-old Rob, I joined the rest of the nation and cried. It was the first of many tear-filled moments that stretched over several days.

The scenes, the heart-wrenching scenes: the night arrival at Andrews Air Force Base, the funeral procession to St. Matthew’s Cathedral, the burial ceremony at Arlington National Cemetery.

That period of mourning was interrupted by a shocking scene in the basement of the Dallas police station: the entire nation an eyewitness to Lee Harvey Oswald’s murder by Jack Ruby.

More had happened, however, than I realized at the time.

The assassination changed expectations.

The dynamism and beauty that had come to be called the New Frontier ended. John F. Kennedy died in Dallas. But the American presidency did not die with him. The president’s heart stopped, but the nation’s never missed a beat.

At 12:30 p.m. Central Standard Time, the 35th president of the United States was assassinated. At 2:38 p.m. CST, Lyndon Baines Johnson was sworn in as the 36th president of the United States, an oath of office administered by a federal judge under the authority of the Constitution.

U.S. armed forces worldwide continued their daily troop counts, assembled in units of varying sizes, policed their surroundings, cleaned weapons and trained. The Army’s day continued to end with “Taps.”

The lights stayed on at the Capitol.

Government carried on.

That was the lesson of five decades ago: People — revered and reviled, weak and powerful — come and go. Strong institutions endure.

America remained on course in the midst of that tragedy at Dealey Plaza in downtown Dallas.

Nov. 22, 1963, teaches us that no political figure is indispensable in this country. No one person carries the nation. And it was no time for partisan politics.

That lesson needs to be borne in mind today.

What kept us on course in ’63 was respect for law and a reliance on a regular order that requires abiding by established rules and procedures, starting with the Constitution.

If ever there were a time when political encroachment or power grabs by the opposition could have developed, it was following the sudden death of a president. That did not happen.

In retrospect, we witnessed the fulfillment of George Washington’s wish for America during that sorrow-filled weekend 51 years ago. The country remained on a path which “gain[ed] time to our country to settle and mature its yet recent institutions, and to progress without interruption to that degree of strength and consistency which is necessary to give it, humanly speaking, the command of its own fortunes.”

And today? What of today’s capital? “Government shutdown,” “legacy of lawlessness,” “obstructionism,” “gridlock,” “impeachment”?

W.B. Yeats’s “The Second Coming” comes to mind:

“Turning and turning in the widening gyre

The falcon cannot hear the falconer;

Things fall apart; the centre cannot hold; . . .

The ceremony of innocence is drowned;

The best lack all conviction, while the worst

Are full of passionate intensity.”

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