He had left Washington for a weekend in Massachusetts - a couple of days of fence-mending in his home state and a bit of rest on Cape Cod - and when he showed up for a speech in Marblehead on Saturday morning a reporter from a Boston television station was waiting for him with her camera crew, waiting with the question.

"Uh, Senator," she began, and when she finished moments later, he was waiting with the answer.

Uh, well, as I, uh, have said before, uh, several times in fact, I, uh, I expect the prersident to be, uh, renominated, and I expect him to be reelected and I, uh, I intend to support him."

The reporter was disappointed. Perhaps she had thought he would announce his presindential candidacy in Marblehead, Mass., to her. "I heard that answer before," she groused off-camera.

"Oh, uh, that's all right," said Edward Moore Kennedy, tilting his massive head and smiling down on her. "I, uh, I've heard the question before too."

It began, of course, with Bobby's murder in 1968, as though there were some binding tribal law that demanded him in lieu of his brothers; but he said no and said it promptly and persuasively and then worked with whatever energy and passion he could muster for Hubert Humphrey - and after Nixon was ensconced in the White House, it began all over again and he did not immediately dismiss it.

After all, by 1972 he would be 40 years old, just three years younger than Jack when he was elected. After all, by 1972 he would have a full 10 years in the Senate, two more than Jack when he was elected. After all, Jack and Bobby had always said he was really the best politician in the family - and so, although he knew his still grieving mother would probably frown on the idea, he began to think about it and began to allow others to discuss it with him and make tenatative plans in his behalf and quickly made his first overt move by defeating Sen. Russell Long of Louisiana for the post of assistant majority leader. The job was more drudgery than drama, but he knew it established him as something more than one senator in a hundred.

With great zest and zeal, he threw himself into his new responsibilities, impressing many of his more senior colleagues with his energy, his sense of fairness, his instinct for equitable compromise and his organizational acumen - and Kennedy, in turn, found the Senate increasingly satisfying as a way of life and means toward other ends.

He was, as they say, rolling. Then, at just about midnight on July 18, 1969, while Neil Armstrong and Edwin Aldrin and Micheal Collins were hurtling toward man's first landing on the moon, a black Oldsmobile hurtled off a narrow bridge on Chappaquiddick Island, Mass., landed on its top and sank in eight feet of dark, briny water. The next day, as divers retrieved the body of Mary Jo Kopechne from the car, the assistant majority leader of the United States Senate confessed that he had been the driver.

He had taken a wrong turn on the way to the Martha's Vineryard ferry after a post-regatta party, he said. He did not know how he had escaped the upside-down sedan, he said. He had made several futile dives, trying to resucue her, he said, and then had stumbled back to the party and summoned three men to help him. After they too failed to bring her up, he said, he leaped from the ferry slip and swam against a strong current the 500 yards between Chappaquiddick and Edgartown where he walked to his hotel and went to bed. A week later he offered a guilty plea to a charge of leaving the scence of an accident and received a two-month suspended sentence.

The events made 1972 immediately out of the question (though Democratic nominee George McGovern did offer him the vic presidential berth). There were simply too many unanswered questions - and the question then became whether 1976 was feasible. By 1974, it has begun again, and again, within the small, loyal circles close to him, he allowed its discussion, gave his permission for tentative soundings to be taken and then dropped it when those soundings showed an enormous journalistic curiosity about that evening in July five years before. His announcement was tersely clear, Shermanesque. He would not under any circumstantces be a candidate for president in 1976 - and despite prodigious pressures on him to change his mind and run, he was adamant. He sniped at Jimmy Carter occasionally during the primary season but then rallied to his side after his nomination and stayed there until - until some time last year when the president's public standing turned brittle and began to break away in significant chunks, and then it all started again for Kennedy and he began, ritualistically, to respond to the question with the answer: he expect Carter to be renominated, expects him to be reelected and intedns to support him in 1980.

It has since become a mantra, never varying in tone or syntax - always the same wellhoned, well-practiced phrases, always the same carefully chosen verbs,expect and intend , always suggestively negative but never quite definitive, never quite Sherman-esque. It sounds like no , but it isn't no , not by a long shot, and he damn well knows it.

"Oh, that's just not true," he argued mildly after returning from Massachusetts to Washington for another week's work in the Senate.

But the verbs - they're so, so precisely vague -

"I, uh, I don't think so. No, not at all vague if you -"

- in the language of politics.

"Well, uh, you know, uh, the answer isn't contrived," he insisted, looking just a little bored with the conversation. "It's just, uh, just an answer to a question I, uh, I'm frequently asked and I, uh, I'm satisfied with it, with, uh, the answer."

"But wouldn't a simple "no" -

"Well, uh, as I, uh, said -

sufice, or a simple "yes" for that matter? Wouldn't that better -

"I, uh, I think I'm happy with the answer I, uh, I've given. I, Uh, don't see any reason to, uh, change it at the, uh, present time."

The present time?

"Yes."

But maybe later, maybe later you might?

"Well, uh, as I, uh, have said before, uh -"

Don't you want to be president?

"What?"

Don't you want to be president?

"Well, uh," he replied, smiling again as he had smiled at the disappointed reporter in Marblehead that Saturday morning. "I, uh - sometimes, yes. Yes, maybe sometime."

But that isn't the question essentially - whether he wants to be the presidnet of the United States. He does. He most certainly, most definitely does. The idea has been there since Nixon edged Humphrey, waxing and waning of course, but always there, perched up on a little niche in his mind. Of course he wants to be the president of the United States. The important question these days though is whether his desire for the office is fierce enough, deep enough, urgent enough in the summer of 1979 to offset and overcome his instinctive reluctance to seek it in 1980 - and that is precisely the question he himself is grappling with as the embryonic campaign begins to take shape and form. How much does he want it? What price is he willing to pay to pursue it?

His stock answer to the question of his candidacy - expect and intend - seems cleverly designed to serve a dual prupose. Since it does not finally close the door to him, it keeps alive the speculation and interest that provide him with the sort of national platform he enjoys for the legislation he cherishers, often in direct opposition to the Carter White House. In the week before his trip to Marblehead, for instance, he called a press conference - artfully staged in the Senate caucus room where his brothers had announced their presidnetial candidacies - and proposed a national health insurance plan far beyond anything the president has envisioned - and then, with scores of reporters at hand and dozens of cameras clicking and grinding away, he challenged Carter to come in with him on the proposal. The effect was precisely what he had thought it would - be top of the show on all the networks' evening newscasts, page one across the country, and a Newsweek cover to boot.

Indeed, there are those, both in his camp and in Carter's, who have concluded that Kennedy's refusal to utter a firm no to 1980 is based on nothing more than his ideolgical urge to keep Carter honest, as when his blast at the president's oil profits tax - "a transparent fig leaf." he called it - produced so much ink and air time that Carter was forced to respond rather unpresidentially that Kennedy's view was "a lot of baloney."

But there is substantially more to the senator's current tactics. By sticking to his answer that he expects and intends , he may go on about the business of being a candidate without actually being a candidate, which is exactly what he is doing. And exactly what Carter is doing. The president, also plagued incessantly by reporters asking what he thinks of Kennedy's answer to the question, told a reporter at his May 29 press conference, "I'm not an announced candidate . . ."

Were Kennedy already announced, it is doubtful he would be involved in anything much different than his present schedule of activities - speeches here and there at various Democratic events across the country, ready availability to an eager journalistic corps on almost any issue that suggests comment, a moderately high profile that has him busily engaged in the work of the Senate.

Most importantly, however, he is using his answer as a stall, buying time while he tries to answer for himself the summer's most salient question. How much will it finally cost - not in dollars but in the currency of his soul? He is treating the question with a scholar's patient acuity. He is in no hurry to make a final judgment. It is, after all, the 10th anniversary of Mary Jo Kopechne's death, a chronological milestone whose passage is now prompting reams of copy in scores of stories such as this one. In 1974, the fifth anniversary drew similar attention and he watched and waited and measured and read and, finally, he said no . He is watching and waiting and reading and measuring now. There's no rush.

"Why should I, uh, do anything now, uh, that is if I really planned to do anything at all?" he asked. "Every time he, uh, - the president - every time he goes down, I, yh, I go up."

It had been a busy, busy week for him. In addition to his duties as chairman of the Judiciary Commitee - the prestigious and powerful post he inherited this year from Mississippi's James O. Eastland - he was heavily involved in the planning for his health insurance press conference as well as appearances on the Senate floor and in several subcommittee hearings. Moreover, the weekend plans for Massachusetts offered no picnic either. He flew to Hyanis on Friday night in a chartered plane (he has little dread of flying, despite the crash in 1964 that severely injured his back), took a chartered helicopter up to Marblehead on Saturday morning and then spent the remainder of the day in the little machine, clattering over to Clinton for two appearances there and then to Worcester for a commencement speech at Assumption College and finally back down to the Cape. On Sunday, he was in Boston for breakfast with a local union and the graduation address at Boston University, then back down to Hyannis and back to Washington on Monday morning.

He did not see his wife.

They separated last year. She moved to Boston, enrolled in college, admitted publicly that she had a problem with alcohol and gave up the rigors of being a Washington political wife, a role to which she attributed at least a part of her drinking weakness. He said he admired her candor in a women's magazine story she wrote about their marital problems, but he would not talk specifically about her blunt assertion that she had been deeply wounded by the rumors of his affairs. There was no need for comment, really. Their friends knew by then that the marriage was in shreds, had known it for quite some time, and they also believed that both of them had a hand in its disintegration. Even their older son's loss of a leg to cancer had done little to bring thme closer. It had, in fact, increased the growing chasm between them by adding to the pressures she felt. Finally, she moved to Boston and no one who knows them well believes she will ever come back. Several who know them well believe that it's because he will not allow it. Few who know them well are surprised to hear that, unlike Betty Ford and other prominent public figures who have aired their alcoholism, she has made little progress with her drinking - and some who have watched her life in Boston suggest that she has made no progress at all.

They were married 20 years ago. "It's all over," a friend says. "There'll be no divorce - she won't hear of it, and I'm not so sure he wants one either - but it's all over. There's no doubt about that." After 20 years, they seldom see each other now, and when he does visit her, an aide goes along. He is never alone.

So you resent it, Senator, when somebody raises Chappaquiddick or Joan or your, uh, your reputation as a, uh, as a -

"Oh no, no, not at all," he said easily. , uh, I realize there's a certain amount of legitimate interest in, uh, such matters, and I've dealt with them, I, uh, I think in a proper way, in the public record."

But, as a matter of fact, Senator, have you dealt candidly with the questions - all the questions - about Miss Kopechnej's death?

"Well, yes it's there in the public record, I, uh, think. I, uh, I've answered the questions before -

Not to everyone's satisfaction.

"To my own satisfaction and the satisfaction of the authorities, and - "

To the public's satisfaction, the voting public ?

"Oh, I'm probably the least best able to, uh, judge that. I, uh, I'm aware that it's a factor, but it's one of a, uh, I would hope that politically my support would be based on my 17 years in the Senate, my, uh, record on issues that are vital to the American people - inflation, jobs, education, crime, clean air, clean water, energy. That's what I would hope any judgments of me would, uh, would be based on."

So, your're not running in 1980?

"Well, uh, as I've told you, I, uh, - "

Are you bored with the question?

"What? Bored?"

With that question, uh, on running against Carter?

"Well, uh, as I've said, uh, several times in fact, I, uh, It expect the president to be renominated and I expect him to be reelected and I intend to support him."

That sounds vaguely familiar .

"Well, uh, the question isn't exactly new, either."

From his staff, considered by many to the absolute best on Capitol Hill, comes a predictable echo of Kenndey's careful disclaimers, and, in all fairness, it should be noted that many of those who are closest to the senator seem genuinely persuaded that he is not a candidate for 1980, that he will not challenge Carter, no matter how glamorous the call for his entry becomes.

Ironically, there are probably more White House staff members who believe he will make the race than those in the Kennedy office who would agree, a "worst case" approach that is still essentially subliminal among the president's people. The official line at the other end of Pennsylvania Avenue is that because Kennedy is "an honorable man," he is being taken at his word that he is not in the running.

Thomas P. O'Neill, the speaker of the House, agrees. He says Kennedy told him flatly that he would not and could not be a candidate while his mother, Rose, is alive - and others report having been told the same thing by the senator, a man who has come to believe that should he ever go after the White House, someone will come after him with a gun.

"Well, uh, it would be foolish, I think, not tobe aware of that possibility," he said. "And, on the other hand, it would be, uh, unbalancing to dwell on it, wouldn't it?

And would that - that fear of being assassinated - would that finally keep you out of a race for the presidency - someday?

"No," he said. "No, I don't think so."

But the potential grief and trauma for his mother and the rest of the Kennedy clan is one of the principal negatives at which the senator is looking these days as he bides his time and waits and watches to see the effects of the Chappaquiddick anniversary. He has said as much to one confidant, said that he did not believe his mother could take another one .

He is also weighing, as another negative, the situation with his wife. He regards her, it is said, as a grave liability, politically, and believe that should he decide to run, at least in 1980, her problems would become his. "Chappaquiddick he thinks he's over," an associate said. "That remains to be seen, of course, but he thinks, and I tend to agree, that he's probably taken most of the beating he can take on that. With Joan, it's a little different story because that raises his, uh, his reputation, and it starts all the gossip all over again, and it's - well, it's something to think about, at least."

He was right about one thing. The gossip seems to have abated. Not since his rumored fling with Suzy Chaffee has another romance surfaced, and among his circle there is now a grudging admiration for his discretion in such matters.

Not least among the factors he is considering these days is his great love for the Senate. After 17 years, he has become a part of the power elite in its workings, and it has become a home for him, complete with the respect and acceptance of most of his colleagues. With the chairmanship of the Judiciary Committee and his seniority, he seems well on his way to one of the most powerful careers in the history of the legislature - and given the fragility of a president these days, it is not an altogether unattractive future for him.

And finally, there is another significant negative for him to mull over in the next few weeks and months. While most measures of public opinion show him to be a winner in any contest with the president for the Democratic nomination, the polls do not suggest a similar advantage in a general election against the Republicans. Even among his most optimistic counselors there is the nagging, gnawing fear that such factors as Chappaquiddick, his marriage and his personal life would become much more pertinent in a contest with the GOP nominee than in any battle with Carter in the primaries. While he has often suggested that he believes he begins any such campaign with at least 45 percent of the popular vote, the uncertainties of some of his lieutenants have made an impression on him.

For Edward Kennedy, not running at all is much to be preferred over running and losing.

But the pull is ever so steady and strong. Write-in movements are already underway in a few primary states, despite his disavowal of them. Party veterans all across the country are edgy about having their local candidates on the same ticket with Carter, and while John White, the chairman of the Democratic National Committee, has predicted a bloodbath if Kennedy gets in, there is considerable sentiment on the committee itself that without the senator as the nominee, there may be no party worth mentioning in 1980, bleeding or otherwise.

And there is no sign yet that the clamor for him will soon subside. In the middle of the week after his weekend in Massachusetts, for instance, five liberal congressmen called a Washington press conference to announce their intentions to make a presidential race "irresistible" to Kennedy. White called to inform the senator that he intended to call their efforts "divisive," but Kennedy was out of the office.

To be truly human is to shape your own world. The senator was speaking that afternoon in an old stone church perched at the crest of Capitol Hill, and that, he was suggesting, had been the essential lesson of Mary Murtagh's life. She was on his payroll as a legislative assistant and she had worked hard, very hard, in his behalf, but more importantly, she had also been his constantly loyal friend and painfully honest critic. That was a rare and joyous mixture, especially in Washington, and he knew it, and when an aneurism had killed her so suddenly in the midst of springtime, just short of her 39th birthday, he had sat down at his desk and wept.

And so he had come on that damp, dingy May afternoon to St. Joseph's Church for yet another funeral, joining her family and her many other friends in a memorial service that mourned her death by celebrating her life. He had freted a bit about the possibility that the mere fact of his physical presence might overshadow the moment - as he knew it so often had on other occasions - but when he reached his pew he relaxed slightly and sat listening the quiet prayers and soft-spoken eulogies and those marvelous, magic Irish songs that always sound so faraway no matter how near they're played - the music that Mary had loved. That, after all, was why they were there.

Then, somehow, when he strode stiffly up to the ornate pulpit to offer his own tribute, the focus began moving subtly from her to him, and when he said what he said about what she had taught him, the shift was abruptly complete, and he knew it.

To be truly human is to shape your own world. He meant, of course, to express a larger, more general, perhaps an existential truth; but the idea, once actually articulated by him, seemed to drift immediately off course, turn in a tight little circle and blow back on him alone, wafted along by some strong counter-current he seemed to generate himself.

To be truly human is to shape your own world. He was simply eulogizing Mary Catherine Murtagh, of course, nothing more; but the sentence as he spoke it - in that flat, familiar New England twang - seemed instantly to wrap itself about him instead, winding around and around him, binding him to its import, a semantic bandage, neatly tied with no loose ends.

To be truly human is to shape your own world. He was talking specifically about someone else's life, of course - Mary's - not his own; but no sooner had the words escaped his lips than they seemed to bank and wheel sharply back toward him, frightened birds skittering home to their nests.

And that is how it is with Edward Kennedy these days - all these easy images, all these facile ironies, all these made-to-order metaphors. He says one thing and means one thing, and yet, inevitably, something quite different is made of it. It is a most curious process. The singular texture of his life, with its abundance of tics and traumas and triumphs and tragedies, has somehow come to match almost perfectly the various textures of the American society. The contact points between his life and the life of the community around him are now so finely, delicately meshed - node and hollow, point and counterpoint, protuberance and depression, good and evil, ball and socket, past and future, tongue and groove, hope and despair, lock and key, ennui and excitement - that an amazing emotional and psychological weld has formed. He is inextricably cast in any and every role his neighbors on the planet may envision for him: heroic ideologue, perfidious villain, Democratic messiah, irresponsible party-wrecker, courageous torch-bearer, reckless playboy, champion, rogue, gentleman, cad, the only child of Camelot, the lone survivor of Chappaquiddick.

Something entirely remarkable is happening among us these days. Somehow, through the chemistry of history and politics, Edward Moore Kennedy is simultaneously becoming not only American's favorite son but its favorite son-of-a-bitch as well.

And in 1984 he will be the same age Jimmy Carter was in 1976. CAPTION: Pictures l and 2, no caption; Picture 3, While Joan now lives in Boston, Ted Kennedy and their children, including Patrick make their home in McLean. Picture 4, The family at Robert Kennedy's funeral in 1968, Presidential speculation about Ted began after Bobby's murder, as though there were some binding tribal law that demanded him in lieu of his brothers. Photographs by Ken Regan/Camera 5; Picture 5, Were he already announded, it is doubtful that Kennedy would be involved in anything much different than his present schedule of activities - speeches here and there at various Democratic events across the country, ready availability to an eager journalistic corps on almost any issue that suggests comment, a moderately high profile that has busily engaged in the work of the Senate.; Picture 6, no caption, Ken Regan/Camera 5; Picture 7, Ted and Joan sailing last fall off Hyannisport. These days Kennedy is weighing the situation with his wife as a negative to a candidacy. He regards her, it is said, as a grave liability, politically.; Picture 8, Kennedy at home with his family, from left, Teddy Jr., Joan, Patrick and Kara, Ken Regan/Camera 5; Picture 9, the two unannounced candidates: President Carter warmly greeted Kennedy, a returning member of the U.S. delegation to the funeral of Pope Paul VI in Rome. AP