WAY PAST midnight, one steamy weekend last August, David Clarke's aspirations met the Good Word, and 3,500 people at the United House of Prayer for All People were the witnesses.

The night before, Clarke, campaigning for the chairmanship of the D.C. City Council, had appeared with the rest of last summer's political hopefuls before Bishop Walter McCollough and his congregation. The patriarch's blessing could certainly turn the tide in a tight election. The candidates spoke. At 6 feet 5 and 250 pounds--so big he always seems uncomfortable with his size--he might have simply towered above the others. But more importantly, Clarke was 'umble, as they say in the southern underbelly of Washington. He had asked not for votes, but only for prayers.

Now the moment had arrived.

"I'm going to stir things up," said the bearded McCollough.

He turned and pointed. "Clarke," he said. The surprised candidate and the bishop embraced. On the way to his car Clarke told an acquaintance he was on "Cloud 13."

Now, the stirring-up rests with Clarke.

In November, he won six wards, got as many votes as both his better-known opponents, Sterling Tucker and Arrington Dixon, and more votes than Mayor Marion Barry did in his election. Earlier last year even his own polls said he had low name recognition, and that a white couldn't get elected citywide because of "racial distrust." Yet by January and the inaugural breakfast, both times he was introduced Clarke received more applause than Barry.

He is now first in the line of succession. If anything happens to Barry in the next four years, Clarke will be mayor until an election. And if Barry decides not to run again, Clarke has eased on the runway as a leading contender for the job.

For the first time in its short history of elective politics the city would be led by a man who is white, albeit a man who cut his political reputation on the same civil rights issues as the rest of the city's leadership quartet--Barry, D.C. Del. Walter Fauntroy and the Rev. David Eaton, a city school board member.

He would be a man who is a font of compassion, who doesn't hesitate to take home a derelict or bring blankets to a burning apartment building, but who is also an unregulated furnace of temper--he can yell unrelentingly at his staff. He's a man whose first career choice was the ministry, who goes regularly to Calvary Baptist Church--yet he supported reform of sex statutes and a bill to ease the severity of marijuana laws, thus earning political embarrassment.

There may be contradictions but after eight years of paying dues by paying attention to the details of the city's patchwork Ward 1, sprawling across some green, some grimy spaces from Howard University, through Columbia Heights and Adams-Morgan, to parts of Embassy Row, David Clarke, at 39, has become the second-highest elected official at the District Building.

Nevertheless, some contradictions won't go away.

In 1974 his campaign posters became a point of controversy when, because of poor art work, he appeared dark; some accused him of trying to pass for black.

Last fall Clarke got an election-night call from Sen. Edward Kennedy (D-Mass.) and the black turf protectionists wondered why. At one of the first City Council meetings, the Rev. Jerry Moore (R-At Large) wanted to know why so many white people were being hired for high positions at the District Building.

Some feel Clarke hasn't faced the issue of the city's racial problems squarely. Last April, he dropped out of the race for two weeks because his own poll said a white couldn't get elected. When he reversed that decision, he said he hoped his running would correct any tensions, but skeptics believed it was a ploy.

Some feel he is racially naive. One insider remembers his skepticism about the depth of racial animosity among the firemen who testified last year before the city's Office of Human Relations. The hearings were tense, with most of the whites sitting on one side of the room and the blacks on the other. Clarke returned to his office shaken. A former staffer says he was close to tears.

Clarke doesn't know what to say about the argument that the local political structure should be preserved as a black institution and that it would certainly be ironic if Dave Clarke, champion of minority causes, was the spoiler in that design. "I haven't focused on it that much. I look at it from the perspective of a Washingtonian. There are people in both races I know who if elected mayor will spoil the institution of self-government," he says.

Clarke's career has been carved in Washington because these are the streets, the institutions, the issues and the people Clarke has known since his youth in the old Southwest and Shaw neighborhoods.

He wants his private life kept that way. His father died before he was born and his mother, a teacher and government clerk, died after a long bout with cancer when Clarke was 16. At Western High School, he competed more at baseball than academics, then became enticed by the political business of Washington, first out of anger.

Over two ham and cheese sandwiches in his office, he recalls his political ignition: "I guess if I grew up in Bethlehem, Pa., I would want to work in the steel mills. But I grew up in the District of Columbia. Government was all about me."

So near and yet so far: "I wanted to be a page, so I was told, 'Go see your congressman.' I didn't have one. That stays with me today." In the early 1960s, he continues, "I got involved with the civil rights movement, coterminously, by getting involved with the home rule effort. When the peace movement came along, I stayed with the civil rights movement and home rule effort because that was my dignity at stake."

After finishing George Washington University where he studied theology, Clarke joined the Free D.C. Movement and D.C. Coalition of Conscience. "He was a young white man who had embraced our vision," recalls Walter Fauntroy. Clarke worked out of Fauntroy's church, doing the staff work that lead to reform of the public assistance system. In 1966 Clarke was arrested for protesting the Cherry Blossom Festival ball (because the general manager at the hotel where it was held was a member of the Board of Trade, which opposed home rule). A year later he became the director of the local bureau of the Southern Christian Leadership Conference.

There, Clarke found a role model and father figure in Frank Reeves, one of the deans of civil rights law in Washington. "He taught me that a person who is happy in his work has reached nirvana," he says.

They didn't make any money but they haggled over legal issues until 4 a.m. at ad hoc offices ranging from the old Cecilia's, to the Southern Diner, to Wings and Things. In 1969 Clarke finished Howard University Law school.

Limited though the positions were to the politically hungry in Washington 20 years ago, Clarke managed to touch all the fundamental bases, including the Pilot District Project on police-community relations. He practiced law. And he learned lessons, especially, as he puts it, the critical one of perspective. His first jury trial in the early 1970s was defending Hosea Williams, who had been arrested after a verbal battle with a cleric at St. Patrick's Cathedral in New York. During the jury selection, Clarke wanted to eliminate one man because of his conservative looks.

Clarke recalls: "Hosea said 'He's from the Post Office. I used to work with people from the Post Office, they are okay, put him on the jury.' And he was one of the first two jurors to vote for acquittal."

When Clarke ran for City Council in 1974, he was earning only $5,000 a year. When he succeeded the appointed Tedson Meyers, his colleagues didn't perceive him as a powerful force. At a retreat in Annapolis, right after that election, he was the one member not given a standing committee. Then Clarke was appointed chairman of a special committee. He built it into a power base, arguing for better housing conditions, ranging from rent control to a condominium conversion moratorium. Less successful was his fight for chancery restriction legislation, which provoked Congress's first reversal of home rule powers.

He rarely stops working. His staff details 18-hour days. He insisted on typing his own stencils during the campaign. He has an exacting pride that makes him read all letters that go out from his office.

"I deny that I am a workaholic because a workaholic is escaping from something," says Clarke. However, when he vacations on Cape Cod and rides 30 to 40 miles a day on his bike, he also finds time to talk to local legislators.

"I've gotten where I am because of hard work," he says. "Hard work is a lot of what I have."

* David Clarke snaps, everyone says. So in the opening weeks of his tenure, he has tried for a reasoned softness in his words. But it's been patience with an edge. When budget emissaries appeared--and the mayor didn't--before the council to explain the fiscal 1984 budget, Clarke was picky and sarcastic: "You've asked this council to bite the bullet. But you are holding all the ammunition and the mayor is not even coming into the shooting gallery." He once even banged his head on the wall, and has yelled so loudly that the people in the adjoining office looked out the window to see if there was a fight on the street. He has thrown up his arms and snarled at key constituents.

Says Clarke: "When a person of big stature says something, people become intimidated . . . and it's much more noticeable. I am not denying on occasion I have gotten angry."

* Clarke delivers. Some events are public record, such as the fight over the Anthony Bowen YMCA. Others are more private. When a neighbor called to complain about a dead rat in front of her home, Clarke wrapped his hand in toilet paper and picked it up himself. He's comfortable sitting in popular Columbia Road bars playing backgammon, and attending small receptions of the Alley Library and the proposed City Museum. Little mileage, but people remember. There's a sentimental side, too. He met the request for a eulogy to a political worker by reading the words of the Frank Sinatra anthem, "My Way."

* Clarke pontificates, some feel. He corrects his colleagues' word usage and legal terminology, and since he is the only white male on the council, some members find this patronizing. His eyes glaze over when talk is about the smaller matters of government--the dirty dais or the official car allotment, for instance. But now he doesn't cut these discussions off, as he once might have.

"I have a great sensitivity to the handling of perks. My strategy is to build trust, to try to show them the old way of doing things is over," he says.

* Clarke believes. In 1974 he boycotted the city's inaugural breakfast, saying he didn't think he should pay to pray. "I really have a greater sense of my own being than being chairman of the City Council. My own sense of my own worth comes from my belief in Christianity. I believe I have a calling." Says a former aide: "He just wants to help, he wants to grow up to be Mother Teresa."

* Clarke is philosophically narrow, some would say. He is, say both his friends and detractors, "a little people's man." But Marion Barry says that is a mission, not a limitation. "He brings a sensitivity to the least among us, a desire to make the government respond."

H.R. Crawford (D-Ward 7) explains that it is a matter of balance: "Some of our enclaves are interested in survival, others the stock market, others whether we are going to have dinner. He is making an all-out effort to have a cohesive relationship with all of us." A less partisan view comes from the former president of the D.C. League of Women Voters, Ruth Dixon: "I'm pleased with the way he is presiding, a cool, good parliamentarian. He's bending over backwards to be patient. And Clarke doesn't suffer fools gladly."

* Clarke puzzles. One night about five years ago, he was seen walking down 18th Street with his face covered with dark smudges. It looked like blackface. He has an explanation: "It was probably engine grease. I fix all my cars." The day after he was stabbed twice outside his Mount Pleasant house in 1980, recalls a friend, "All he wanted was a Big Mac." He even puzzles himself. Describing that night, he says, "You know, I started to run after those guys."

* Clarke survives. When the sexual assault bill became public, the assault turned out to be on Dave Clarke. Hundreds of calls, thousands of letters, denunciations from the Rev. Jerry Falwell and company. "I wake up and on the front page of The Washington Post is a story, not about the change which had taken place in 34 states, but somehow that I am trying to legalize teen-age sex." But no one brought it up during last year's campaign except Clarke.

At their turn-of-the century home, decorated with antiques and painstakingly restored, Clarke's wife Carole remembers how she moved to Washington to work with Vista and, she says laughing, "save the city."

One night, Dave Clarke came to visit one of her roommates, who wasn't home. She was attracted to him, she says, "because he was hard to understand. He was obviously very intense, obviously had strong opinions."

After nine years together and one son, an important part of their balancing act is to respect each other's solitude. "Dave works things out by walking, biking, reading the Bible, he gets to the Book of Judges and starts over again . He does his own life," says Carole. She wears sneakers, white corduroy slacks and a brown and white poncho pullover. She grew up in a blue-collar town of Brockton, Mass., and after getting her degree at the University of Massachusetts, Amherst, came to Washington,

As a teacher of children in crisis, who are unable to attend school because of accident or disease, Carole Clarke works in her own pressurized and intense world. "No, he doesn't really," she says when asked if her husband shares her crises. "I know that's a thing with a lot of people, but I enjoy being alone."

Says Clarke: "We talk about this. She deals with problems that I consider are almost unmanageable. She amazes me because I couldn't. Those are pressures I couldn't deal with."

It is a political household. In all the campaigns, the couple has agreed to keep the headquarters in the house. Typically, almost 80 percent of the workers have been elderly women. One had to use a walker to get around. The operation, says an amused Clarke, "drove the labor union and downtown financiers bananas."

As for now, David Clarke wants to worry about the next four years, but a lot of Washington is thinking about what happens after that.

The competition for mayor four years hence, discounting a Barry rerun, appears to be slim right now. Insiders speculate that if full home rule ever became a reality, other white politicians such as John Hechinger would save themselves for the Senate. And conceivably race could work in Clarke's favor. Fauntroy feels it did in the last election: "Many crossed both party lines and maybe ideological ones."

Yet Barry believes that "the voters . . . will keep some balance in the city."

The question remaining is whether Clarke can grow beyond his longstanding role as civil rights advocate and champion of "the little man."

Clarke has no answers. Except to say: "If I had an answer, I think it would inhibit me from doing this job. I am already crazy enough to run for this job. I can be crazy enough not to know what I want to do next. I wasn't supposed to get this job."