These are years when the upward movement in human affairs goes way up and changes the course of our country for the good, or the down times that go far down and change our nation's course for the worse.

Forty years ago, 1968 became one of those years when the downward move was deep and long-lasting.

"How lucky you were to work directly with John Kennedy, Robert Kennedy and Martin Luther King," a reporter told me during my 1991 race for the U.S. Senate.

"Some luck!" I replied. "All three of the men who meant the most to me in public life were killed."

Minutes later, realizing I didn't want those words to stand, I called her and said that of course I was lucky - we were all lucky to have had them even for such a short time.

John Kennedy was on his way to becoming a great president and might have ended the Vietnam War and given new leadership to the world. So I believed, but we will never know.

His assassination did not trigger a long national depression of the spirit. Lyndon Johnson was ready at Day One to pick up the fallen president's torch. In the tragic aftermath, the grace of Jacqueline Kennedy also helped, as did the words of Martin Luther King Jr. as he lifted sights to the unfinished work needed to fulfill the American dream.

The mid-'60s became an era of social invention and public action. "We the People," through our Congress, led by a president who promised "We shall overcome," enacted the legislation to achieve the two prime goals of the civil-rights movement: ending publicly enforced segregation and ensuring the right to vote for all Americans. And we went on to launch a war on poverty that Kennedy had talked about but had not had time to start.

By 1968, however, "We the People" were torn apart by Johnson's decision to go ever-deeper into a war many of us thought was a mistake. It drained resources from the War on Poverty, and also from the Peace Corps, a smaller endeavor in which I was engaged, which Kennedy hoped would make a substantial contribution to the world.

Young voters rallied in surprising numbers to Sen. Gene McCarthy's primary campaign challenging the wartime president. An agonized Lyndon Johnson decided not to run again. JFK's brother entered the race "to save the soul of the country." Then, Martin Luther King Jr. was killed.

At King's funeral, after the long silent march across Atlanta, Kennedy asked me to take leave from the new college I was heading and campaign for him in California. I said yes.

At the beginning of that decade, Attorney General Robert Kennedy thought I was too emotionally involved with the civil-rights cause to take a post in the Department of Justice. By 1968, there was no major political figure more passionately committed to achieving civil rights, ending poverty and stopping the war than Robert Kennedy.

We will never know whether he would have won the nomination and the election, or been able to bring the nation together for a new course. But looking back, we can see that the sad spring of 1968 and the turmoil that followed did start a depression of the spirit from which it has taken a long time to recover.

In November 1968, Richard Nixon was elected. After his downfall in the Watergate scandal, President Gerald Ford said: "The long national nightmare is ended." I don't think so. Sen. Ted Kennedy likes to say, "The dream lives on." Nightmares can live on for a long time, too.

The nightmares that linger and haunt us are the assassinations and the thousands of lives lost in the civil-rights movement and Vietnam.

For me at least, that spectre of violence now takes the form of the war in Iraq. What Kennedy said in 1968 could be said today: "For it is long past time to ask: What is this war doing to us? Of course it is costing us money . . . but that is the smallest price we pay. The cost is in our young men, the tens of thousands of their lives cut off forever. The cost is in our world position - in neutrals and allies alike, every day more baffled and estranged from a policy they cannot understand."

Reflections about 1968 can serve as a warning of what can go wrong at a turning point. We may be at another historic turning point today. A large majority of Americans believe the nation is on the wrong track, and many now fear that we will not overcome the crisis in our economy. As an antidote to fear, we need to look at times of trouble when we made the right turn. The best example of that is the election of Franklin Roosevelt in 1932 and the first 100 days of his presidency in 1933.

Recently, I took a break while campaigning for Barack Obama and I immersed myself for a few hours in the Roosevelt museum at Hyde Park, next to FDR's home on the Hudson. I came away recharged, with high hopes for this election and the days of action that bring this country together and for the soul of our nation. And that this turning point is upward. *