‘Don’t you feel like a traitor?” the radio interviewer asked me in 1980, “having been Jimmy Carter’s New York campaign manager in 1976, and now working against him four years later for Edward Kennedy?”

“No,” I said. “I was working for decent and intelligent government. We didn’t get it, and I’m still working for decent and intelligent government.”

Agree with Ted Kennedy or not, as often I do not, he has worked for better government all his life. Often he has been underestimated, though never by his fellow senators, and rarely by serious students of the issues he champions.

Personally, I have never seen a politician demonstrate physical courage more clearly than Senator Kennedy did when he campaigned for Jimmy Carter in 1976 at the garment center rally on Seventh Avenue.

The New York Police Department pleaded with us not to have Mr. Carter, let alone Mr. Kennedy, appear on an open stand in the middle of the avenue. But Teddy spoke on that open stand and built a crowd of tens of thousands of people packed building to building across the avenue for blocks in each direction.

People wrongly think of his 1980 campaign against President Carter as an embarrassing failure, a misperception largely based on his television interview with Roger Mudd. Like his brother in 1968, Mr. Kennedy was reluctant to oppose an incumbent president of his own party. During that period of indecision, he taped an interview with Mr. Mudd. Later, CBS aired the interview without making it clear that the show had been taped before he decided to run, thereby making Mr. Kennedy seem irresolute in his own behalf.

At first Ted Kennedy’s campaign was a lonely effort. When I went down to Florida to join a volunteer “Draft Kennedy” campaign before the senator had formally announced his candidacy, the only other old hand I found helping him in Miami was my friend Allard Lowenstein, the intellectual center of the dump-Johnson movement in 1968.

When Senator Kennedy’s 1980 campaign finally got underway, it was masterfully run by Steve Smith, the brother-in-law and campaign manager of the three political Kennedys. But, like Robert Kennedy’s in 1968, it was another late start. Ted’s one hideous misadventure still haunted him, and the party was not ready to change candidates.

There was no time to build a new organization. Old friends had to do the job. Money was short. Every week five or six of us met in Steve Smith’s house to plot the New York campaign. We had all worked in Bobby’s 1968 race, and we all knew what each of us had to do: labor, minorities, money, scheduling, and my own job, building the committee of New Yorkers for Mr. Kennedy. With his blue-eyed twinkle and tough mind, Steve held us accountable and invigorated the campaign, but we all knew we were working not just for Ted but also to restore a vision for the future of our country.

After a slow start in the early primaries, the campaign gathered momentum. Each day the senator was more assured, more on-message, more his own man. On the final primary day in June 1980, Mr. Kennedy won all six primaries, including New York and California, by a total majority of over 250,000 votes, more than John Kennedy’s plurality against Richard Nixon in 1960 in all 50 states.

But altogether Ted won only 10 primaries. Trailing in delegates and the popular vote, he soldiered on through the summer until losing the nomination to President Carter at the convention in August. Due to that extended campaign, some Democrats still blame Senator Kennedy for Ronald Reagan’s victory in November 1980.

Instead of being withdrawn or resentful in defeat, at that convention Ted gave the great address of that presidential year, one that still echoes in that sonorous Irish-Boston voice, reminding us all why the Kennedy brothers have inspired our political life.

“It is the glory and greatness of our tradition,” he said, “to speak for those who have no voice, to … fulfill the aspirations of all Americans seeking a better life in a better land.” In the fraternal tradition, he concluded with Lord Alfred Tennyson: “I am a part of all that I have met. … Though much is taken, much abides.”

How easy it would have been, after that defeat in 1980, for Ted Kennedy to have retired from politics and indulged himself, or at least to work and pose like an average senator, enjoying power and rarely leading.

Instead, for more than a quarter century, he has worked harder and better. As Senator McCain said recently, Ted Kennedy “remains the single most effective member of the Senate if you want to get results.”

But there is something more about this senator than political accomplishment. Perhaps it is a cheerful acceptance of the limitations of his own illustrious life, a quality of good humor and good-heartedness, and a stylish self-deprecation that has endeared him to both allies and adversaries.

Who could not recognize this when he left the hospital, a stranger to self-pity, joking with the staff, happy to be going home to the sea, and to be going sailing with his wife. Who would not wish to sail with him?

Mr. Bull, whose most recent book is “China Star,” served as Robert Kennedy’s New York campaign manager in 1968.