DAVID STOCKMAN, a man so often perceived as an icy ideological zealot, has a new program these days: marriage.

He seems to approach it with the fervor of a religious convert, not unlike every other crusade he has been on in his life--from his days as an anti-war activist to his year at Harvard Divinity School, where he once fancied a run at the clergy, to the right-wing fiscal policy of supply-side economics.

After a well-publicized bachelor life, the director of the Office of Management and Budget flew Jennifer Blei to the Bahamas last summer and proposed on a pier in the gleam of the Caribbean moonlight. "It was eloquent, I assure you," he says. He asked that she take his name.

During a recent dinner at their Dupont Circle condominium, David Stockman talked about the couple's new Royal Doulton china pattern, and how he has even restructured his workaholic habits to be a good husband. Instead of staying at the office late he comes home at 7 p.m. to be with Jennifer, and rises at 4:30 a.m. after 5 1/2 hours' sleep to get the paperwork done.

They talk about starting a family soon--perhaps having two children, never only one. They finish sentences for each other. When he singes a well-known economist, calling him a "little twirp," she reprimands: "Sweetie, that's a slight exaggeration." And he backs off. On weekends, they go to the Safeway. Together.

"David's whole demeanor and body language change around her," observes a friend and political ally. "He becomes much more boyish, a little less confident, more like a kid. David seems to be either a 64-year-old graying senior statesman or an 11-year-old boy."

If he's obliged to attend a political dinner without his wife, an OMB staff member notes, he sulks.

"There's a definite sense of commitment," explains Jennifer Stockman, as her husband devours crab claw appetizers. "You function as a unit. David is so involved in every aspect of our life. Like the personal finances. Even grocery shopping. We plan those kinds of things. We go together."

"There are functional reasons," interrupts David Stockman, speaking in typical Stockmanese. "She can't carry the bags."

This is a far cry from the public perception of a callous David Stockman, the human adding machine. White House aides, the joke goes, huddle around his heart during summers to keep cool.

Even before the Reagan inauguration, David Stockman, now 36, had emerged as a walking computer spitting out an avalanche of economic forecasts. His face appeared on the cover of all the major newspapers and magazines. He was the GOP's savior, the public's hope. Even the Democrats were listening. A shrewd political operator as well as a brilliant statistician, Stockman seemed to have left few stones unturned. The administration's first budget resolutions, with Stockman at the helm, sailed through Congress.

Then, on Nov. 12, 1981, he offered his resignation to the president because of what he called "careless ramblings to a reporter." In the now-famous Atlantic Monthly article by William Greider, he expressed serious misgivings about the administration's economic programs and the feasibility of supply-side economic programs. Among other things, he told Greider the administration's forecasts were carelessly developed and he described Reagan's supply-side across-the-board tax cuts as a "Trojan horse"--a means to sell the "trickle-down" theory that reduces the rate for wealthy taxpayers.

Within 11 months of his impressive ascent from obscure Michigan congressman to the nation's top economic whiz kid, David Stockman managed to irreparably damage the faith held in him by all his constituencies: the White House, the supply-siders who got him the job and the public.

Theories abound on why Stockman decided to spill all to Greider: opportunism, the indiscretion of youth, raw ambition.

"I don't want to judge his motives," says longtime friend and economic mentor Rep. Jack Kemp (R-N.Y.). "I would not have done it. I think there was a drop after that . . . I was just disappointed, not upset. I'm friendly. I went to the wedding."

The most popular dime-store psychology was that Stockman knew the public and the president would eventually recognize the problems and he wanted to be on the record with the news first. He was depending on the fact that the article would not be published until a year after the interviews.

This reasoning--more than the "careless ramblings" notion--jibes since Stockman expresses similiar misgivings in a forthcoming book by Laurence Barrett, "Gambling With History: Reagan in the White House." Stockman's interviews with Barrett were conducted around the same time as the Greider interviews.

"Shows I'm consistent, doesn't it?" says Stockman across the near banquet-size dinner table in his apartment, when he is asked if he is concerned about the Barrett book. "The press never goes to the same well twice. And events will fairly well confirm that some of the things I was concerned about were valid."

Today, 19 months after the Greider piece, the entire budget process is in disarray, with the Senate, the House and the White House all at odds. Rumors of Stockman's departure are again in the air. No, he says emphatically, he is not planning to leave after this budget. "It seems to be one of the favorite spectator sports around here."

And did he learn anything from the Greider debacle?

"Well, it made me realize that everybody can make mistakes-- they're fairly easy to make," he says.

"Does anyone want coffee?" interrupts Jennifer, after a dinner of Chicken Cordon Bleu, wild rice and fresh fruit, which he served.

"I would," says her husband. "Sweetie, would you mind making some or do you want me to do it? Sit down. That's my job."

The Stockmans live in a two-bedroom condo that Jennifer bought last year. It looks as if the decorator just left. The decor is entirely hers, ultra-contemporary in white and blue with smoked glass and mirrors, the antithesis of what one would expect from a man born on a farm in Michigan, a man who attended a one-room school and read its entire library by the time he was in the third grade.

"I wouldn't allow his stuff in the apartment," she says. "It was all brown, very boring male furniture. It wouldn't even make an interesting den."

"Okay, that's enough," he says. They gave it all to his brother.

"Sweetie, the cat is out again," she pleads.

"Well, I keep putting him in the room and you keep letting him out," he sighs. "I'm going to put him back in the room."

There is a blue oriental rug, blue floral couch and white love seat. Selected Waterford pieces are arranged with precision in the wall units. There are no books in sight. The dinner table is smoked gray glass, set with blue and white china, white chairs, spring flowers. Jazz musician Al Jarreau is crooning softly in the background.

"I think it was just that after you date someone . . ." she says, starting to explain why they married now. "Well, we had dated for 4 1/2 years."

"Since June 17, 1978," he offers in the name of accuracy.

The relationship was not an easy one, and is probably as good a testament as any that opposites attract. Blei, an IBM executive who during her selling career exceeded her husband's salary, is the product of a suburban Philadelphia, upper-middle class upbringing. Her father is an oil broker, her mother owns an insurance agency. She has a sense of style and always looks impeccably manicured and tailored. Her words are equally tailored. There is an aura of glamor and poise about her.

They met when he was a congressman from Michigan and she was selling computer systems on the Hill. They moved in together, and then moved back into separate apartments when he was named to the OMB slot. At the time, friends said she was not thrilled with the arrangement. Soon his name started slipping into gossip columns linked with other women.

"What I did was I went away a lot," she says of those days. "I took myself on a few vacations. I kept myself very busy. I totally immersed myself in work, so my schedule was equally demanding. That's what I did to not have to really deal with that."

Following the Greider uproar, the relationship seemed to cement. Stockman went underground for at least a year, and began operating as an insider instead of as the front man. His name vanished from the gossip columns and he began showing up around town with Blei. They decided to marry.

But back to Greider.

"The interpretations were so preposterous," he says while making coffee. "It made me realize that it was sort of a hand-me-down process. The third guy interpreted the last two guys who read the article, using unequivocal flat statements that weren't even remotely related to what was quoted or the context. Everyone was saying I admitted juggling the numbers. I never juggled the numbers and the article doesn't say I did that."

But it did say, he is reminded, that he admitted to not understanding the numbers.

"Yeah, well nobody does."

But wasn't he supposed to be the god of the statistics?

"They're the ones that said that. I never said that. All these stereotypes, all these mythologies."

But didn't he, himself, believe he knew it all for a while?

"I understand them better than anybody else," he says with an air of resignation, "but I don't understand them."

It is precisely this kind of statement that evokes in critics such as Arthur Laffer, and others, a distaste for Stockman.

"I don't think he has a philosophy," says Laffer, a founding theoretician of supply-side economics. "He's not principled in that he doesn't have a guiding view of how the world really works. He can simultaneously recommend contradictory things and not feel the twinge of the contradiction. He is not guided by principle or theory. But only psychologists can answer what he's doing in this field. He is a very ambitious young man."

Stockman says he has beliefs. He perceives himself as both an ideologue and a politician. His economic philosophies were self-taught 10 years ago when he became intrigued with the free-market economy and read everything from economic classics to propaganda pamphlets. He once said he viewed himself as somewhat of a libertarian--a person who believes in the doctrine of freedom of will, which politically translates into opposition to governmental interference.

As for his conservative and supply-side detractors: "They're looking for a scapegoat," he says slouching back in what he calls his "favorite" white chair. "Since realities turned out to be more complicated and difficult than they figured, there must be some perfidious individual that caused things not to come out the way they predicted. So they picked out me. According to those people, I singlehandedly caused the recession. No one has done that since Herbert Hoover."

"I don't think David is an ideologue because he is much too critical and introspective," says a Republican who has worked closely with Stockman through the budget process. "He is highly manipulative, extremely ambitious, a bright guy who has swayed in his own personal beliefs from one side to another fairly dramatically. He has no long-range philosophical agenda. I don't think he is as motivated by money as he is by power. If it came to power and visibility versus money, he'd take the power."

Does Stockman actually know what drives him? Is he motivated by specific goals?

"There's nothing mystical about it," he says. "Did you ever see some mechanically inclined kid tear down the engine of a car for hours and hours trying to figure out how it works and put it back together to make it work better? That's what I'm doing.

"Do I know what I'm trying to do in my professional capacity? Yes. Do I know all the answers? No. Do I know the problems? Reasonably so. Do I think there is a simple formula? No. But I know these things have to be dealt with, so you try to deal with them as capably as possible."

The wedding was small and cozy last February, the day after one of the worst blizzards in Washington history. She has taken his last name in her private life.

"At work I'll call myself Jennifer Blei because I don't want to be immediately pegged to David. I want to be known for me and my contribution and not put people off."

In addition to her furniture and Smokey, the Siamese cat, Jennifer also brought her maid into the marriage. She is probably the primary domestic crisis in their lives right now. She comes Fridays and leaves notes in unusual English, he says.

"She yells at us all the time through these notes," she says.

"Every week she has a problem," he says.

"The new vacuum cleaner, for instance," she says.

"She asked for one for six months, so we got her one and she didn't like the kind," he says.

"We got her one of these new modern ones--very portable, very light," she says. "So she leaves me a message. 'Ms. Stockman, the thing you got me is like a toy, please return it.' Now this note tonight. She was asking for some Windex or whatever and I didn't get it for her because I was out of town the whole week and I forgot. But her note was in the same place where she left it. So this note said that she was very angry we didn't read her last note."

"She also has a hard time with Smokey," he adds.

David Stockman once said that he has never needed to write a re'sume'. And there is almost as much speculation on his future as there is on whether Reagan will run again. Jack Kemp thinks Stockman will "end up as a successful Wall Street businessman, only to be surpassed by his wife." White House aide and friend Richard Darman speculates that Stockman is not interested in money, just policy.

"What do you mean by that?" he says, when asked if Darman's insights about money were accurate. "I'm not a fanatic. I'm interested in public policy and economics and government. That's not to say you can't make money doing it. Not in government, but a lot of people make money advising. It's probably the most lucrative business there is. Take Alan Greenspan. He has a tremendous firm. It's not just government-oriented, but he's constantly in the government process from the distance. So there are a lot of different roles."

Stockman says he will write a book because he believes he has something to say, but he has ruled out elected office again, as well as another four years in the administration.

"I don't think anyone could do that," he says. "It's not just the time, it's the constant conflicts in this job. You know, why aren't the secretaries of Education and Interior in conflict? They're not. I'm in conflict with everyone. It's intrinsic to the position. Everyone is knocking on the door."

His ideal job, he has said, would be editorial page editor of The Wall Street Journal, functioning as a conservative economic and business voice for the largest circulation daily newspaper in the nation.

"Okay, what does that do?" he asks. "The editorial page of The Wall Street Journal is very influential in that it shapes opinion on the daily course of government and public policy. So, umm, I was using it more as symbolic. I'd like to be in the debate."

"Well, David would be very good, but the job is full," says Robert Bartley, editorial page editor of the Journal. "I wouldn't quit to be director of OMB . . . He's very facile and very very smart, he knows the issues. That's what it takes."

The issues. The debate. David Stockman has been on many sides, it seems. But is it true he moves from crusade to crusade without ever finding a home with any of them?

"No," he says. "I don't think I'm a moth heading for a light bulb."