Marion Barry's 1978 victory was a long shot, brought home by his ability to be "one of us" to an unusual coalition of Washingtonians who made his campaign for mayor into a crusade.

Former civil rights activists joined with police and firemen. Young developers seeking a signature on the city's skyline coalesced with neighborhood activists opposed to K Street-style development. There were gay activists, school teachers and an impatient, up-and-coming middle class fed up with inefficient city government.

Barry has delivered in part on major campaign promises to make the city's bureaucracy more efficient and courteous, to improve housing, to increase jobs and economic development and to run a competent government.

Yet during the 3 1/2 years he has been in office, he has repeatedly broken special-issue promises to some of the faithful and scattered some members of the original Barry army.

At the same time, he has skillfully used the largess of incumbency to build a new base among businessmen, developers and minority contractors who spurned his candidacy in 1978.

With the campaign barely beginning, the new army has given Barry twice as much in campaign contributions as any of his challengers--$600,000 in bragging rights.

"They are supporting me because I'm a good politician. I know how to win," he told a reporter recently. "They may say they don't like me. I know that. But they'll tell you I'm a good politician and they know it. It don't matter if they don't like me . . . If people who don't like me vote for me, I'll be mayor again."

Yet as the campaign for the Democratic nomination begins in earnest, Barry's standing in the polls is unusually low for an incumbent--27 percent in the most recent survey. Financial support is one thing, political popularity is another.

Just as Barry, who replaced Walter E. Washington, now echoes the former mayor in explaining his shortcomings in office as human imperfection, he also borrows a phrase from Washington to dismiss the political riddle posed by an abundance of financial contributions and the relative dearth of support.

"You know I don't comment on polls," he said the other day. "The only poll that counts is the one on election day."

Others do comment.

"An incumbent certainly would want to go into a race with a lot more support than that," said Peter D. Hart, a prominent pollster who has done a poll for Patricia Roberts Harris, one of Barry's opponents. "Every time you hear him say he is the front-running candidate you've got to turn that around. What he is really saying is 'I'm battling back.' "

Barry's ultimate weapon in the battle is the power of incumbency--jobs, contracts, a 38,000-slot bureaucracy, appointments and in some instances the simple personal magic of being the mayor.

Barry launched an 11th-hour anticrime campaign in the face of growing concern over that issue. After hundreds of layoffs early in his administration, he gave city workers contracts sweetened with long-sought optical and dental benefits and promised no more layoffs if reelected.

Some of those who have been the most shrill critics of Barry in the past are now on the payroll in the Barry bureaucracy. Jonas Milton, a former John Ray supporter, works in the housing department, for instance. Absalom Jordan Jr., a former aide to Barry foe Douglas E. Moore, is head of the unemployment compensation board.

Walter Washington's 1978 campaign manager, Lacy Streeter, still works in the housing department, as he did before Barry was elected. Barry's head of legislative affairs is Barbara C. Washington, whose brother Robert ran Sterling Tucker's 1978 campaign for mayor.

When Barry was looking for a trouble shooter to resolve the community crisis over the closing of the Anthony Bowen YMCA in Shaw, he chose Tucker, who had just dropped out of the race for mayor.

And few in the town's power elite have seemed willing to gamble on backing someone else at the risk of offending the person who will be mayor for at least another seven months if not another 4 1/2 years.

"There may be the perception that if you give to me you'll get something in return," Barry said the other day. "I don't know that it's true . . . I don't handle all the contracts . . . But the perception, it's out there."

The coalition that put Barry in power with a scant 35 percent of the vote in a three-way Democratic primary was an enthusiastic group centered in the changing inner-city neighborhoods of Wards 1, 2 and 6, plus a strong contingent of affluent whites in Ward 3 west of Rock Creek Park.

While Barry was not a winner in the outlying, predominantly black and middle-class wards of the city or in the poverty-riddled Ward 8 in far Southeast, he did have enough support in those areas to minimize his margins of defeat there and win the citywide race.

The Barry campaign organization was able to mobilize around issues important to that patchwork of voters, many of whom were relative newcomers to the city.

Barry's failure to deliver on promises important to those voters has cost him political support in the ranks of the original Barry army. One large chunk of defections came over the related issues of historic preservation, land use and hotel expansion.

As a candidate, Barry opposed expansion of hotels into residential neighborhoods. In 1979, the Washington Hilton Hotel sought permission from the D.C. Zoning Commission to expand and Barry aides testified in favor of the expansion--even though tenants in 339 apartments would be displaced and the character of the neighborhood would be changed. The aides said the expansion would bring the city more blue-collar jobs.

"Marion had flatly promised that he would not allow the hotel to expand," said Carol Currie, chairman of the citywide Citizens Planning Coalition and a stalwart in the Barry camp in 1978. "The people in the building who had been there 40 and 50 years felt he betrayed them. Everyone interested in planning and historic preservation felt he had betrayed us. You can't trust a politician like that."

Candidate Barry also said he would complete a master development plan for the city to replace what critics called piecemeal planning through decisions on single projects. He promised to give citizens more of a voice in developing individual neighborhood plans that would eventually become part of the master plan.

"There have been excuses and alibis to explain how he double-crossed us on planning and historic preservation," said Ann Hargrove, who supported Barry in 1978 and is a Barry appointee to the Mayor's Downtown Committee. "He said he would continue doing what Walter Washington had done and more.

"There have been no neighborhood plans since Barry was elected," Hargrove said. "He's done nothing to protect the old downtown. Since he's been in office he doesn't want to see us and hear about planning or historic preservation. I'd rather have Walter Washington back."

Barry now says he will complete the master plan by election day.

He also pledged as a candidate to oppose commercial development along the Georgetown waterfront, but his historic preservation officer decided last year to permit such development. That made political enemies of some former Barry supporters in the Citizens Association of Georgetown.

Barry explains that change by saying that, since he took office, he has learned enough about the historic preservation process to realize that his campaign promise on the Georgetown waterfront was one he could not keep.

Another promise that drew support for Barry in 1978 was his commitment to improve public schools. Yet up until this year, when he proposed a something-for-everyone election-year budget that proposed sharply increased school spending, Barry, citing declining enrollment, has contended that the school budget should be reduced proportionately.

"Since he's been there he's cut the school system's budget regularly and said over and over that he can't do anything about the schools" said Marilou Righini, copresident of the Parent-Teachers Association at Wilson High School and a former Barry supporter who says she now supports D.C. Council member Betty Ann Kane for mayor.

"When he was running he said he'd find ways to be involved because education was a priority," Righini said. "Parents involved in trying to make the D.C. public schools work know him as the enemy."

The unions who broke ranks with organized labor in 1978 and went for Barry instead of Walter Washington have faced tough times under Mayor Barry, who had promised access and a sympathetic ear.

He backed away from supporting the teachers' union during their 23-day strike in 1979, and teachers were among the hardest hit by layoffs stemming from the city's financial crisis. The police union that backed Barry supported the hiring of more police with money made available by Congress. Barry did not.

The firemen's union that supported him watched as their mayor moved to close two fire stations, eliminate nearly 100 jobs by attrition and for months delayed promotions and salary increases to await the outcome of lengthy hearings on a discrimination suit.

"You have to wonder what he would have done if we hadn't endorsed him," said William E. Mould, president of the International Association of Firefighters Local 36.

"I don't want to make any comment on Barry at this time," said William H. Simons, president of the Washington Teachers Union. "We'll be looking at what the Central Labor Council and others do . . . But it doesn't matter to us whether the candidate we endorse wins or loses. We have an agenda and we know where we want to go."

The International Brotherhood of Police Officers, which was the bargaining agent for city policemen when Barry ran for mayor and endorsed his campaign, has since been voted out and replaced by the Fraternal Order of Police.

As mayor, Barry has often been at odds with policemen over the size of the police force and its budget."We haven't reached the point where we are ready to endorse anyone," said Gary Hankins, chairman of the labor committee of the FOP. "I think it's fair to say that there have been problems between Barry and policemen. As for police protection in the city, police morale is not very good under Barry. I don't think the crime rate has gone down under him, has it?" Hankins said.

During the 1978 campaign, Barry also promised to include more women in the government, to help women feel safe in the streets and to help middle-class, single women buy homes in the city. Women were one of Barry's largest constituencies.

Barry says that nearly half of his appointments to boards and commissions have been women and that the number of women holding mid-management jobs and above has increased from 26 percent in 1978 to 33 percent now. Among them are several key department heads, including the budget director, corporation counsel and director of finance and revenue.

"His appointments have been significant," said Ann Turpeau, former head of the D.C. Commission on Women, "but it's also true that there's no major department in this city headed by a woman . . . . I'm talking about police, fire, human services and down the line . . . All the women's jobs are Cabinet level jobs only if you expand the definition of Cabinet agency."

Lavonia Fairfax, head of the Coalition of 100 Black Women, said, "I think he's had some women in visible posts. But there are not enough women in strong positions. Once you get behind the few women he's got up front you won't find any more women in middle-management under him than there were before.

"It's like the churches. Women do the work but the men--the deacons and the minister--are the power base."

Not all of Barry's former supporters have been disenchanted; not all have lost during his first term in office.

More than three dozen homosexuals have been appointed to boards and commissions, including the Alcoholic Beverage Control Board and the Police Civilian Complaint Review Board. Gay rights political activist Richard Maulsby is head of the mayor's office of motion pictures and television development.

"The mayor has been openly supportive of gay people and their rights throughout his time in office," said Tom Bastow, former president of the Gertrude Stein Democratic Club, the city's major gay rights political organization.

"The most important thing is his influence on the police," Bastow said. "In most other cities the police often harass gays. Here the mayor has set the proper tone. He had Police Chief Maurice T. Turner and Assistant Chief Marty Tapscott sit down with us and they've been very cooperative."

Among the groups Barry is reaching out to are minority contractors, many of whom supported Tucker in 1978. Their major complaint then was that they had received an insufficient share of the city's contracts, despite a law targeting 25 percent of all contracting dollars for minorities.

Under Barry, minorities have received 31 percent of all city contracts and 43 percent of the construction contracts, as compared to 15 percent of all contracts and 29 percent of construction contracts under Washington. That translates into $115 million in contract dollars under Barry as opposed to $30 million in the previous administration.

"And you can believe," Barry told the contractors in the audience at a recent Georgetown cocktail party where $100,000 was raised for his campaign, that "I'm going to do more in the next four years so we all profit even more."

Barry has also made inroads into the city's unions and churches far beyond the range of support he was able to claim in 1978, even though some of his efforts have been late coming.

The recently signed contracts, for instance, have won friends for Barry in the public employe unions.

"No matter what problems we've had, we can't ignore what he's done for us in those contracts. They are very good for us. I guess you could say its a matter of how long our memories are," said Bernard Demczuk, legislative and political affairs coordinator for the American Federation of Government Employees, which represents about 10,000 D.C. workers.

"Right now I'd have to think that most public employe unions will support him because of the contracts," Demczuk said. "I don't know about the private employe unions. They don't have to get their contract from him."

But the election is still four months away. Unlike 1978, when Barry was clearly the most liberal and distinctly different candidate in the field, he now is running against a new generation of city politicians whose political bases overlap his own--both past and potential. Three of the seven are D.C. Council members; one is a former presidential Cabinet member.

And while Barry has the overt support of many, others remain uncommitted. Leaders of the city's church community, for instance, off and on considered a potent political force in Washington, generally have either remained noncommittal or scattered their support.

Barry has heavily increased spending for the elderly, a group of highly dependable voters who in past years were rock-ribbed Walter Washington supporters, but their preferences are not now clear.

Private sector labor unions have yet to take a stand, another round of major campaign contributions from businesses is still to come, and the campaign organizations that will be so crucial on Sept. 14 are only now being organized.

The real campaign has just begun.