THE PHONE CALL FROM GARY HART THAT SATURday night in May could not have come as a surprise. A shock, yes -- bad news shocks -- but not a surprise. For months, the warnings, rumors, tips, threats, sightings, gossip and innuendo about Hart's extramarital sex life had been floating like so much flotsam and jetsam into the Denver campaign headquarters. Bill Dixon was beyond surprise. He'd keep telling himself, keep reassuring his staff, that it was all "background noise" -- the sort of treachery and trivia and nonsense that has a way of glomming on to any front-runner's presidential campaign. He was determined not to let it distract him.

Yet the din kept getting louder. Within a matter of days, it would obliterate a candidacy that had been 14 years in the making. Some in the Hart campaign knew it was over the moment they heard about that Saturday night phone call. Others say they saw the inglorious end coming even earlier.

Not Dixon. He was Hart's campaign manager, a friend since they met during the anti-Vietnam war political battles a decade and a half before, and he considered Hart "someone who has more character in one little finger than anyone I've ever met." Beneath a hard exterior, Dixon was, at age 43, still very much the idealist and true believer, someone who still viewed political campaigns as crusades. When Hart had asked him at the end of the 1984 election to run his Senate office and manage his anticipated 1988 presidential bid, Dixon had hesitated six weeks before saying yes. He didn't thirst for power, didn't care for Washington, no longer craved the thrill of the chase. But finally, he did say yes. His reasoning was simple: He felt obliged to do whatever he could to keep his kids from getting blown up in a nuclear war. To people who didn't know or understand Bill Dixon, the rationale seemed melodramatic, sanctimonious, naive. To him and his fellow crusaders, what could be more important?

Hart's phone call that Saturday came moments after he had confronted three Miami Herald reporters outside his Washington town house. In an agitated voice, candidate told campaign manager that the reporters apparently had been conducting a surveillance and were about to publish a false story saying he had spent the night with a young Miami woman, Donna Rice. Dixon was livid. Within hours, he would launch a fierce public battle to save Hart's candidacy and reputation. But in less than two days, Hart's loyal friend would quietly resign from the campaign.

Dixon has never revealed his reasons; he will only hint at them even now. He says he concluded he "could no longer be of use to the campaign" after he discovered for the first time on Monday that Rice had been Hart's companion on a boat trip he'd taken the month before to Bimini. Hart hadn't told him about that trip during their conversations Saturday and Sunday.

Did Dixon leave because he felt betrayed by his candidate? He won't say. Did he intend his own resignation to signal Hart that he too should get out? He acknowledges only that it's an "interesting" question. He says his "actions speak for themselves" and prefers to stick to the basic narrative: He got on a plane that Monday night, flew back to Denver, "unplugged my phone, put on the television and started watching baseball games." He made no public statement of any kind, and only a handful of people in the campaign knew he was gone. Even fewer understood why. 1600 DOWNING STREET -- COULD THERE BE A more auspicious address for a presidential campaign headquarters? The street number evoked the White House; the street name the British prime minister's home. Actually, the address is the classiest thing about it: The five-story brick building is squat, boxlike, nondescript. It sits in a yuppified residential neighborhood a mile east of Denver's shimmering post-modern skyline.

There, starting around the first of this year, three dozen presidential campaign veterans began setting up shop on the top two floors. They came from all over the country; many had quit jobs or sold businesses or uprooted families to be there. They all had anti-establishment leanings, and most were alumni of two previous Hart crusades -- the 1972 presidential campaign, which Hart had managed for long-shot Sen. George McGovern, and the 1984 Democratic primaries, during which candidate Hart sprung out of nowhere to nearly upset Walter Mondale.

This one felt different from the others; it felt, in a word, winnerish. It wasn't just that Hart entered 1987 with a massive lead in the polls. More important to the staff arriving at 1600 Downing, he seemed to start out with a franchise on all the best ideas.

It was a common belief -- call it a conceit -- at campaign headquarters that 1988 would be fought over turf Hart had laid out before the nation in 1984: a leaner military, a revamped foreign policy that placed less emphasis on the East-West struggle, a set of industrial strategies to spur productivity, a rejection of special-interest politics, a move toward national service, a heavy investment in education.

There was one worry: Hart didn't like talking about himself. And in an era when so much about presidential politics played out before the naked eye of television, the Denver high command knew that the "who" of a campaign counted every bit as much as the "what." Probably more. But to coax Hart into exposing his innards to public inspection was an enormous chore. His campaign staff kept trying to figure out ways to "humanize" Hart; he kept resisting. He did write and distribute a 5,000-word autobiographical sketch, "One Man's Luck," that delivered a couple of requisite boyhood anecdotes, but only enough to whet the appetite of the great media curiosity machine. To feed it, an early April visit to his boyhood home in Ottawa, Kan., was arranged; there, Hart choked up at a town meeting as he spoke of his love for his deceased parents. It was the most emotional he had ever been in public. The staff was pleased. The candidate wasn't. He had also been suffering through lengthy interviews for profiles; the more the media asked, the antsier he became.

"I am an obscure man, and I intend to remain that way," Hart told free-lance journalist Gail Sheehy in 1984. "I never reveal who I really am."

The armchair psychiatrists on the Denver staff and in the press theorized that his whole life had been a Gatsbyesque flight from his past, especially from the rigid precepts of the Nazarene Church, for which his devout mother had groomed him to be a minister.

There was also a darker theory -- that Hart had some kind of self-destruct mechanism, typified by his misrepresentations about the name and age changes that became a major issue in the 1984 campaign. This theory was used by some to explain his alleged flouting of social mores by openly carrying on with women. The Washington gossip mill had for years been full of stories linking Hart to Hollywood stars and starlets, colleagues' wives and campaign groupies. They were only stories, but they had taken on a life of their own.

There was one more aspect of Hart's personality that did not mesh with his aspirations -- and may have contributed to his downfall. He was a loner. Even after 12 years in the Senate and with a large early lead in the polls, he had been unable or unwilling to win support from his fellow senators and the Washington political establishment. "He was an outsider, even to his own campaign," says one senior aide, who joined the Hart campaign earlier this year. But in the same breath he adds how appealing he found Hart. "He had a wonderful appreciation for the absurdity of politics. And he had a perfect pitch for floating in and out of the game -- for knowing when to be a player and when to be an observer. I found myself liking him more and more."

NINE FORMER SENIOR CAMPAIGN AIDES AGREED TO BE interviewed for this article, reconstructing the events of what they now call "hell week." Four spoke only on the condition that they not be quoted by name. Hart declined to be interviewed. What is most striking about their recollections is how much information had found its way into the Denver campaign headquarters before the fact, how many concerns had crystallized before anyone heard the name Donna Rice, how many different staffers had sounded alarms privately to Hart in the month before his Washington weekend with her. And how Hart ignored it all.

On one level, everyone in Denver -- Hart included -- had no choice but to pay attention to the so-called womanizing issue. References to stories about Hart's past relationships with women had become a standard paragraph in the articles about Hart written around April 13, when he announced his candidacy. Staff and candidate alike considered this kind of journalism pure gossip-mongering.

Early in the campaign, Hart had assured Dixon, Political Director Paul Tully and National Campaign Cochairman Charles Manatt that he understood he would have to lead a life above reproach in 1988. He knew the press would be probing more into his personal life this time -- partly out of the natural fascination affixed to a front-runner, partly out of what seemed to be a feeling within the press that they had let him off easy in 1984 by not reporting the stories of his so-called womanizing. Everyone in the campaign sensed that whatever the rules had been before, they would be different this time.

The first fleeting published references in March to past womanizing were taken as a kind of warning shot by the Denver staff. But there were also bigger worries. Tips kept coming into headquarters about surveillances of Hart that either had already been conducted or were being planned. And other tips placed the candidate in the company of attractive young women in and around Florida.

Dixon tended not to pay much attention to the sightings with women, but he took the surveillance rumors seriously. In 1974, he had been counsel to the House committee that started impeachment hearings against President Nixon. ("Impeach Dixon, Not Nixon" was a rallying cry of some of the president's defenders.) He knew all about dirty campaign tricks, about how high the stakes could get in a presidential campaign.

He says he heard this spring from a "prominent Washington journalist" (whom he declines to name) that The Washington Post was planning to conduct a stakeout of Hart as part of an expose' it intended to write about Hart's sex life. Another campaign staffer, who asked not to be identified, says he had been warned at roughly the same time by a friend at NBC that the network was planning to do the same thing. (Both The Post and NBC say they neither planned nor conducted a surveillance of Hart.)

There was more. Dixon said in an interview published last month in The Madison (Wis.) Capital Times that he had been told by political sources six or seven weeks before the Donna Rice incident that a prominent Washington political figure had hired a detective to tail Hart, who the politician suspected was having an affair with his wife. Dixon heard that the detective had followed Hart to the apartment of a woman who was not the politician's wife, and that the politician was threatening to make this information public to sabotage Hart's campaign. Dixon said he had put out the word to the politician through intermediaries that he should either "come forth" with whatever information he had, "or he should shut up."

As if this wasn't enough, a law-enforcement official had warned a top campaign aide that someone was planning to infiltrate the Hart campaign with a body microphone to collect damaging information. There was no sex angle, but Dixon took the warning seriously enough to announce at a staff meeting that "everybody in the office who smiles at you isn't necessarily a friend." Dixon also told Hart about the various surveillance threats. "Gary said, 'Yeah, I expect that,' " Dixon recalls.

If Dixon was worried about spies, others in the campaign were troubled by reports of what people who weren't spies had already seen and heard. One top staffer says he had heard from political sources that Hart had been seen in the company of coeds late at night in a bar in Gainesville. Hart spent a week there in March as a guest lecturer at the University of Florida College of Law. Others in the campaign say they had heard he was socializing with a bunch of women at a party in Miami in early April, and Dixon says he had heard secondhand from tourists in Bimini that Hart had been there with a woman (he didn't know it at the time, but the woman was Rice) and a couple of friends.

"I was told they were very open about their activities," Dixon says of the Bimini reports. "They had had their pictures taken with other tourists, and I figured, no problem. Gary has the ability to have a relationship with a woman without sex being involved."

Not everyone on the staff was quite so confident. "When I heard some of those stories, my head started spinning," recalls Ginny Terzano, the deputy campaign press secretary, who had worked for Hart since 1983. "I remember one dinner with some other people on the campaign where some of us started to question what we were doing out there if Gary didn't seem to care."

According to several sources, at least three different staff members -- Finance Director Eli Segal, political aide Hal Haddon and traveling aide William Shore -- warned Hart in separate conversations about the "sightings." Meanwhile, Press Secretary Kevin Sweeney also alerted Hart to the surveillance rumors.

"He was told he was playing with fire, but he wouldn't even entertain the discussion -- he cut them right off," says one top aide, who heard of Hart's reaction secondhand. Another aide heard a different version: "My understanding was that he said he would clean up his act, that he knew appearances counted. Some of us came to the conclusion that he viewed his announcement day sort of like a wedding day, and we figured he was getting everything out of his system beforehand."

When Hart called Denver May 2 to report his run-in with the Miami Herald reporters, some in the campaign instantly feared the worst. "Everything that happened that week, we foresaw," says Terzano. "I cried twice that week," recalls Sweeney, 29, who had worked for Hart since the 1984 campaign. "The first time was when I first heard." Several sources who met with Dixon at a hastily arranged strategy session in his Denver apartment say the specter of "resignation" and "out of the race" was raised that Saturday night. Dixon remembers otherwise. He says he told the staff that how well they responded would be critical to the campaign, and encouraged them to put on brave public faces.

Dixon was enraged by what Hart had told him. He decided that he himself, rather than some lower-ranking campaign official, should be on the scene as soon as possible to act as Hart's spokesman and defender. He flew East that night to do battle. "I figured a newspaper was about to print a totally false story about Gary and I didn't want him to dignify it by responding personally," he says.

For the next 24 hours, Dixon played his self-assigned role to the hilt. "I had the luxury of being righteously indignant," he says. "I went merrily on my way, attacking a story I'd been informed was totally inaccurate." With a mix of full-throated outrage and lawyerly precision, he zeroed in on the holes in The Herald's surveillance ("I'd worked my way through law school working for a private eye. I know all about back doors"), blasted press accounts as "preposterous . . . inaccurate . . . character assassination . . . harassment," portrayed Hart as "outraged," "furious" and "a victim," and said Hart's relationship with Rice had been "innocent."

A day later, Dixon resigned from the campaign.

Meanwhile, at the Denver headquarters, senior staff members were riding an emotional roller coaster that took them from a "sickening" fear that the candidacy had been fatally wounded, to flurries of hope that came with the uncovering of holes in The Herald account, to the sinking realization that, as the focus of press attention began to broaden at mid-week from "incident to pattern," as one staffer describes it, the cause was lost.

Sunday and Monday were days of hope. The first round of press stories and network coverage had not been as bad as the staff had feared. The Herald had published no pictures of Hart with Rice and was backing off from some details of its initial account. Rice had faced the press and acquitted herself well.

Best of all, Lee Hart was holding up like a trooper. Though she was grounded in Denver by a bad sinus condition -- "she said if she appeared in public that first day, people would take one look at her and assume Gary had hit her," one aide recalls -- she was showing the same steadfast support for her husband of 28 years in private that she would later display in public. It wasn't easy. According to several accounts, some of Lee's close friends gathered at the Harts' rustic cabin-home in Troublesome Gulch west of Denver on the day the Herald story appeared and angrily denounced Hart. One friend, in a fit of irreverent anger, reportedly brandished a kitchen knife and proposed that the next time Lee saw her husband, she should "cut it off." Others told her that she shouldn't fly East to be by Hart's side (as she eventually did Wednesday after the sinus swelling came down), that she should "make him come to you."

Lee got moral support, too -- from, among others, actor Warren Beatty, Hart's friend and sometime political adviser, who reportedly phoned the cabin repeatedly to keep her spirits up.

Along with glimmers of hope in the first days of the crisis, there were problems. Lynn Armandt, Rice's companion for both the Bimini trip and the Washington weekend, had dropped out of sight, and the staff was worried about the possibility of conflicting stories. Fund-raising was drying up, virtually no elected officials were willing to speak out on Hart's behalf, and scattered early polls showed massive hemorrhaging of support. "The women were quicker to disqualify," says one senior aide of reports from telephone canvasses. "The men said things like, 'stupid.' The women said they weren't going to vote for him."

On Tuesday, in a previously scheduled speech to a newspaper publishers convention in New York, Hart attacked the press and insisted he had done nothing "immoral" with Rice. Later that night, at a Manhattan fundraiser, he spoke of having taken a "stab in the back," implying he had been the victim of a setup. (Many on the staff had the same suspicions, but no one has been able to come up with any evidence.) But Hart vowed to press on: "I may bend," he told the audience of several hundred, "but I do not break."

The next day, Hart was scheduled to campaign in New Hampshire. His staff had concluded there was no way to avoid a press conference -- scores of reporters were going to be following him, apparently prepared to hound him at every stop about the discrepancies between his version of the Rice weekend and The Herald's. So he decided to "do a Geraldine Ferraro" -- campaign lingo for holding, amid a crisis, a press conference that lasts until the reporters run out of questions. It was set for the Hanover Inn on the Dartmouth College campus Wednesday afternoon.

Sweeney prepped Hart beforehand by running about 20 questions past him. One was whether he had had affairs in the past. Hart told Sweeney he didn't have to answer a question like that.

A few hours later, he would give the same answer, but in a much more tense and public setting, to this reporter, who asked whether he had ever committed adultery, and to a Boston Globe reporter who asked whether, aside from the period of two brief separations from Lee, his marriage had been monogamous.

Afterward, Hart said he regretted he did not respond with more "indignation," Sweeney recalls. "He said on the way to the next event that adultery is a matter between himself, Lee and God, and he doesn't have to answer to anyone else."

If Hart was disturbed by the tone of his answer, his staff was alarmed by the direction of the questions. "When you have papers like The Washington Post and The Boston Globe asking questions like that, it didn't take a rocket scientist to figure out what was going on," says one staffer.

"The questions sent a real message," says another. "We assumed they were a setup for another context. You could see this story going from incident to pattern." All week in Denver, the staff had been picking up rumors that one paper or another was planning to write stories about other affairs Hart allegedly had had.

That evening, at a town meeting in Littleton, N.H., Hart was encouraged when the audience asked him questions about arms control, not adultery.

But his frustration was mounting. To escape from the press horde, he and a small party of aides made a last-minute switch of hotels and spent the night at the Colonnade Motor Inn in Lyndonville, Vt., about 25 miles from Littleton, where the press and other Hart staffers were staying.

Hart, his wife and half a dozen aides had a long dinner that night at their hotel restaurant. Lee, who had flown East a few hours earlier, regaled the group with war stories of the scene at the cabin -- the camera crews camped on the road through Troublesome Gulch, the reporters who had followed Andrea, their daughter, to her classes at the University of Denver. Hart complained that the press was so obsessed with this story, he could not get his message out.

They talked of strategies to fight their way out of the predicament. Someone suggested going directly to the voters by buying a half hour of national television time. That got the Harts' juices going, but not for long. "You'll pay for your half hour," one aide reportedly told them, "and then Brokaw and Jennings and Rather will get on with their half hour and they'll pick away at all the questions you didn't answer."

By the end of dinner, Hart seemed dispirited, according to Deputy Political Director Joseph Trippi. He talked of canceling the next day's campaign schedule in New Hampshire and returning to Denver to reassess his situation.

Not everyone left the restaurant with the impression that the campaign schedule was about to be suspended; the confusion may have arisen because the dinner party had been split between different tables. As the Harts headed off to their room, the aides in Vermont made a conference call to staffers in Denver and started discussing the campaign schedule for the next two weeks. Trippi, who had been at Hart's table at dinner, broke in to say he thought this was premature, that Hart wanted to suspend the schedule.

As they debated, Sweeney, who was at the hotel in Littleton, phoned the Denver headquarters with more bad news. This Washington Post reporter had just presented him with information detailing a liaison that Hart had had with a Washington woman at her town house last Dec. 20. The information was from a report by a detective who had been hired by a man who wanted to find out if Hart was having an affair with his wife. In the course of the detective's surveillance, he had followed Hart to the town house of a woman who was not his client's wife.

The report, which included the name of the woman and pictures of Hart leaving her town house, had been given to The Post earlier in the week. The Post had confirmed with the woman through an intermediary that she and Hart had had a long-term affair.

Sweeney relayed the information to John Emerson, the deputy campaign manager who was one of a troika in Denver running the campaign in Dixon's absence. Emerson relayed it to Shore in Vermont. Shore awakened Hart, asked him to come to his room and gave him the information. Hart then phoned Sweeney in New Hampshire for the details. " 'This is never going to end, is it?' " Sweeney recalls Hart saying in a "sad, sad tone. He then said to Billy, 'Let's go home.' "

But when Hart went to bed for the second time that night, there was still plenty of confusion in Denver, New Hampshire and Vermont. Did "going home" mean quitting the campaign or returning to Denver to reassess? Nobody felt like waking Hart up again to find out. "He'd just gone through the worst day of his life," said Sweeney.

In Denver, Emerson, Tully and Haddon strategized through much of the night. The next morning, with Hart's approval, Haddon phoned Washington Post Executive Editor Benjamin C. Bradlee to find out if The Post was planning to run the story and name the woman.

One Denver source says the purpose of the call was to "inform Bradlee that Hart would be getting out of the race," in the hope of "heading off another gusher." Another Denver source characterizes the intent a little differently; he says it was to inquire whether The Post would publish the story if Hart dropped out.

In any event, Bradlee told Haddon that The Post had not yet prepared a story and did not intend to publish the woman's name.

Once his charter flight arrived in Denver on Thursday, Hart wanted to withdraw from the campaign as quickly as possible -- that night, if it could be arranged. It couldn't. Instead, Hart visited privately with staff and volunteers at 1600 Downing -- including Dixon, who had rejoined the campaign earlier that day after he heard that Hart was about to get out of the race.

That same night, Beatty was on the phone with him, trying to convince him to fight on. He didn't succeed, but he may have helped push Hart into discarding the withdrawal speech that had been prepared. "It was shorter and more sentimental, and I don't think a single punctuation mark survived," says David Dryer, campaign issues director, who had written it. Instead, in a defiant speech to a national television audience on Friday, Hart confessed to having made "big mistakes but not bad mistakes" and denounced the modern presidential selection process as a "mockery" that "reduces the press of this nation to hunters and presidential candidates to being hunted . . . I could see what was happening: I was going to be the issue. And I don't want to be the issue."

With those words, one of the most breathtakingly precipitous tailspins in the history of modern politics was over. A front-runner's campaign had vaporized in a single week's time -- nine months before the first voter would get to cast the first vote in the first caucus. The end came with such stunning speed that what turned out to be the most embarrassing "evidence" against Hart -- a picture of him balancing Rice on his lap during their trip to Bimini -- didn't get published until after his campaign was history.

IN THE DAYS THAT FOLLOWED, HART BEGAN TO HAVE MISgivings about the withdrawal speech. For one thing, he had received a letter of praise from his longtime political antihero, Richard Nixon, who said he admired the defiant tone. There had already been widespread comparisons to Nixon's "last" press conference in 1962. These distressed Hart, and so did the fact that he had not publicly thanked his staff or apologized to them.

Over the following days and weeks, he set out to do that -- in private meetings, phone calls, letters. As far as can be determined, there were no angry confrontations. "He goddam knew better than anyone else how much he had hurt people," says Dixon.

Hart stays in touch with most of his senior aides by telephone and has been asking them to help him find a dignified way to get back onto the public stage. "He's clearly groping," says one. "He's always prided himself on having a good feel for the voters, but he's lost on this one. He doesn't trust his judgment. He keeps saying he doesn't want to look like a fool."

He has talked of writing articles, giving speeches, raising money for his Center for New Democracy, maybe even organizing an issues convention this fall in Iowa. He is circulating a proposal to write an autobiography. He has met with a Hollywood agent to discuss an image repair. He has also been told to lie low -- especially since kiss-and-tell accounts and pictures continue to trickle out. "There is still some blood left in the veins," says one. "If he tries to come forward now, he'll be chopped meat."

Meanwhile, the staff has scattered. Sweeney, the press secretary, took a fly-fishing course in Denver and has moved to San Francisco, where he is looking for work. Emerson has returned to his law firm in Los Angeles. Haddon has resumed his criminal law practice in Denver. Segal, who has known Hart since 1969, has returned to Boston. He is not sure what to do next. "I'm going to take a long summer to figure it out," he says. "I'm just coming out of the mourning period. I've gone from anger to melancholy to resignation to relief, and I can feel myself heading into a nostalgia phase."

Terzano is helping out with Sen. Albert Gore Jr.'s (D-Tenn.) presidential campaign. "Gary messed up his life, but I didn't mess up mine," she says. The only other senior aide to join another presidential campaign is Tully, who is now political director for Massachusetts Gov. Michael S. Dukakis.

Dixon is back in Madison, Wis., where he has hung out his lawyer's shingle. He says he's through with presidential politics for a while. "It takes time for wounds to heal," he says, "and I'm wounded."

Asked what sense he makes of the whole episode, he says: "It was very Kafkaesque. I was a charter subscriber to Mad magazine and this whole thing had that level of absurdity." However, he still has trouble laying all the blame for the campaign's collapse at Hart's feet. "I found it scary to see news organizations . . . in the mass pursuit of naked sensationalism. My favorite cartoon was the one that had an editor saying to 12 reporters, 'You guys find out something new on Gary Hart' and saying to one reporter, 'And you go over to the Iran-contra hearings.' "

What about the Hart campaign? Knowing what he now knows, would he have run it differently?

"Some people will probably write that we were asleep at the switch. But that's not right. I had total control of everything in this campaign," he says, "except his personal life." ::

Paul Taylor is covering the presidential campaign for The Washington Post.