PHOENIX -- Less than 20 miles down the interstate from the copper-domed state capitol at the bustling heart of Phoenix, the Kelly green lawns, aquamarine pools and shocking pink cabanas of the chic outer suburbs give way to the real Arizona: a dusty, slate-gray emptiness where only a few resourceful species have learned to exist in a land without rain.

The rapid transition from desert to downtown alongside Interstate-17 is a reflection of the rapid metamorphosis of this whole state from a parched outback to a booming Sun Belt magnet over the past two decades. As everyone here knows, this shift in the face and fortunes of arid Arizona is largely due to governmental programs assuring the quantity and quality of the state's most precious resource: water.

That is why an elite commission of lawmakers, lobbyists, conservationists and copper miners was willing to spend hundreds of hours here this spring working out the precise details of a labyrinthine new state law governing ground-water quality.

Despite its importance, the drafting of the lengthy water bill was an exercise in tedium that left all the commission members complaining of boredom and fatigue. All, that is, except the group's chairman, Bruce Babbitt, who is the governor of Arizona and a public policy buff of the first order. Day after day, Babbitt presided over windy debates about this clause or that comma -- and seemed to be having the time of his life.

"That's the gov -- he loves that kind of thing," says state Sen. Alfredo Gutierrez, one of Babbitt's chief allies. "What he likes is when you really get deep into the specifics of some issue -- that's when he shines, because he will know the specifics better than anybody else in the room."

Back in Washington, where the political community is just starting to assess Bruce Babbitt's campaign for the 1988 Democratic presidential nomination, the thoughtful Arizonan is known, vaguely, as a "neoliberal" who is willing to break with traditional Democratic dogma.

But here in Phoenix, the talkative 47-year-old lawyer is known best as a man who simply loves the nitty-gritty of governing. Those who have worked with or against Babbitt during his nine years as governor describe him as a master of nuance and detail, as a man who never met a 400-page official report he didn't like.

On issue after issue, these observers say, Babbitt has become immersed in details of policy and procedure that more "conceptual" chief executives -- Ronald Reagan, for example -- might leave to underlings.

"Here's a man who became governor by accident, and he has very carefully studied every lever of power," says James Bush, a Phoenix lawyer who is the state's most prominent lobbyist for business interests. "If he can get what he wants by pushing a law through the legislature, he'll do it. If he can't, he'll sit down and plot out, step by step, a way to go around the legislature."

Babbitt, who spins off the narratives of his many policy battles with the relish of an old sailor telling sea stories, says he based his total-immersion method of governing on lessons he learned at a corporate law firm here.

"The first thing you learn when you're negotiating is, if you don't keep on top of the details, you lose your leverage to really make things happen," he explains. "All I ever learned in a big law firm was, the power is in the hands of the draftsmen . . . . As the architects say, God resides in the details."

The same attention to fine points applies on procedural matters, such as dealing with legislators and bureaucrats, Babbitt says. "There are just thousands of moving parts, and what you have to do is get into the matrix of the process and look for your openings." Making Methods Work Despite Obstacles

Political professionals of both parties here agree that Babbitt's methods can work. They point to the passage of a major ground-water management program in 1980 as the best example of Babbitt-style government.

Ground water is the water supply in underground lakes, or aquifers, as opposed to surface water, which flows in rivers or canals. Ground water is more precious in this desert state than silver or gold; controlling it is the most sensitive issue in Arizona.

Babbitt began work on his 1980 ground-water bill with a bit of melodrama staged to create a receptive attitude in the state. He says he talked to Cecil Andrus, then secretary of interior, and "we actually arranged a little charade that was enormously helpful."

The two agreed that Andrus would threaten to cut off funding for the biggest federal water project in Arizona unless a new ground-water plan was adopted. "I said to him, 'I don't blame you one bit,' " Babbitt recalls, " 'but I'm going to go home and call you a no-good, overreaching federal hypocrite.' "

Faced with this "pressure" from Washington, Babbitt says, he went to the leaders of the legislature and said, "Step aside -- this is too important to screw up."

He then set up a special commission, with himself as chairman, to draft the complex new law he had in mind. Those who took part say Babbitt was clearly more familiar with the intricate details of the plan than anyone else involved.

"The legislature never touched it," Babbitt says, clearly savoring the memory. "We finished it after eight months of negotiation, called a special session of the state legislature , they passed it -- without changing one word -- in a day and went home."

The Democratic governor has used similar ploys -- task forces, study commissions, etc. -- to get around the heavily Republican legislature on other issues as well, including the water quality measure he put together this spring.

In cases where legislative involvement could not be avoided, he has employed the full panoply of executive power to get his way. Among other things, he has issued 75 vetoes during his nine years in office, far more than any other governor in Arizona history. Taking Credit for State Achievements

As a result, according to Don Harris of The Arizona Republic, a leading political analyst, Babbitt has been "one of the most successful governors the state has had in terms of getting his programs through."

Another result, Harris notes, is that Babbitt has gotten the lion's share of attention -- and credit -- for most of the major legislative achievements during his tenure.

On the other hand, Babbitt has maneuvered to stay out of the spotlight when unpopular legislation was passed. After every tax increase during his tenure, he has worked hard to stick the blame on the Republican legislature.

In 1981, for example, Babbitt bitterly denounced legislators for raising the gasoline tax. He blasted the bill in an angry statement, calling the tax hike "an unconscionable fleecing of the public."

Days later, conceding that the state needed the extra revenue, he signed the tax increase into law.

That performance earned Babbitt sharp criticism for being two-faced, but it also led to a memorable one-liner. At a news conference after he signed the bill, a reporter twitted Babbitt by asking whether there could be such a thing as a "conscionable fleecing." Without missing a beat, Babbitt replied: "Some would say that describes my political career."

The political career of this moderate Democrat in an increasingly conservative and Republican state has been a story of hard work, careful timing and good luck.

Babbitt, who majored in geology as an undergraduate at Notre Dame and then went to Harvard Law School, carries a charmed name in Arizona. The name "Babbitt" here brings to mind not Sinclair Lewis but rather the respected mercantile business begun by the governor's frontier forebears. Bruce Babbitt says the family business empire is worth about $20 million today.

After working in an antipoverty law program and at VISTA headquarters in Washington, Babbitt joined a corporate law firm in Phoenix. As a member of a group of reform-minded young Democrats, he was elected state attorney general in 1974 in what he describes as "a classic 'clean-up-the-mess' prosecutor's campaign."

Then lightning struck. Gov. Raul Castro resigned to take a federal appointment, and the secretary of state, Wesley Bolin, moved up to the governor's job. Five months later, Bolin died. Since there was no elected secretary of state, the attorney general was next in line. In March 1978, Bruce Babbitt suddenly found himself in the governor's office. 'Governor by Accident' Turns Activist

In his first four months as "governor by accident," Babbitt vetoed three bills and established himself as an activist chief executive. In November 1978, he was elected governor by a small margin. Four years later, basking in wide approval for his successful ground-water management bill, he was reelected with 62 percent of the vote.

When his current term ends in January, Babbitt will step down to go back to law practice and focus on his presidential campaign.

As he emerges on the national political stage, Babbitt is seen as a thoughtful, intellectual sort, and that is precisely the way he is viewed in Arizona. He is a generally popular figure here, but he seems to generate more admiration than affection among the electorate.

"The gov is not a warm, open kind of person," says his friend Gutierrez, the Democratic leader in the state Senate. "People don't come away with a real friendly feeling about him, but they definitely respect him."

"Babbitt is a loner," says Rob Smith, a Sierra Club official who has worked with the governor on environmental issues. "He tends to want to control the process rather than work jointly with other people on things."

Babbitt is a precise, careful speaker -- he is one of the few remaining politicians who never uses the preposition "between" when proper grammar calls for the word "among" -- who is sometimes given to thoroughly academic public utterances.

Asked recently to explain why, as a Roman Catholic, he supports freedom of choice on abortion, Babbitt replied: "I concluded that the church's position is not exactly identical with the state of natural law, which we use as the ethical basis for writing human, that is, statutory, law."

Characteristically, Babbitt has carefully analyzed this analytic strain in his own nature.

His transition from practicing lawyer to politician has been "painful," he says. "I tend to be didactic in my political speeches. I'm arguing a situation or set of facts to a jury rather than selling myself to an electorate."

At his ranch-style home in a comfortable Phoenix neighborhood (Arizona does not have a governor's mansion), Babbitt seems easygoing and amiable as he relaxes with his wife, a Phoenix lawyer, their two sons and the family's pet snake, Logo. "Logo's really a friendly pet," the governor says as the handsome black-and-white serpent slithers through his arms. "Of course, it's pretty revolting to watch him eat."

But once the governor gets to the office, he reverts to what he has called his "seminar mode," in which he is sometimes not completely sympathetic with those he feels to be less competent.

Describing Eldon Rudd, a Republican congressman from Arizona, Babbitt says: "He looks like a congressman . . . . and beneath it is not an extraordinary amount of depth." Explaining why he formed one of his special commissions on a particular issue, Babbitt said the step was necessary because "the Arizona Supreme Court got it so deleted up."

Although he has high praise for his staff, he notes that "my best periods with the local press have been when I don't have any press secretary except myself."

When Babbitt took time to praise three leading legislators in his state-of-the-state address this spring, local columnist John Kolbe wrote that the governor had done "something utterly out of character -- he conceded a debt to someone else."

In a similar vein, Babbitt draws criticism even from political allies for running a closed-shop administration that leaves important players out in the cold. "He's got this small corps of people, almost all men, that he trusts," says a leading female Democrat here who did not wish to be identified by name. "Outside of the inner circle, I don't think he listens to anybody."

This spring, for example, Babbitt infuriated much of his own party by endorsing a political neophyte named Tony Mason for the Democratic gubernatorial nomination. Many party leaders who back the competing candidacy of Carolyn Warner, an experienced Democratic officeholder hoping to become Arizona's first female governor, say that Mason's only claim to the governor's endorsement is his status as a longtime Babbitt crony.

Still, feminist groups have given Babbitt high marks for his commitment to so-called "women's issues" -- particularly his creation of a Cabinet-level Office of the Child to deal with family concerns. He scores well, too, with other traditional Democratic constituencies, including Hispanics, blacks and Indians. Poor Relations With Organized Labor

In contrast, Babbitt's relations with organized labor are simply rotten. Union members have not forgiven him for calling in the National Guard to quell unrest at the big copper strike in Morenci in 1983. To this day, union leaders around the country boycott Babbitt's speeches.

The state education union is also cool toward Babbitt, who has been outspoken in supporting testing for teachers.

Conversely, the governor has won praise and some political support from the business community. "Over the years, he has been pretty receptive to business, at least for a Democrat," says James Bush, the business lobbyist.

"Particularly when we were working on interstate banking where a Babbitt task force wrote a plan that pleased the banking community , I came to the conclusion that the man is a deregulator at heart."

Environmental groups here say they are generally pleased with Babbitt's record. "He knows the outdoors, he talks about it with real feeling and he generally takes a strong position," says Rob Smith of the Sierra Club.

Smith says conservationists have been disappointed, though, with Babbitt's failure to crack down on copper smelters believed responsible for a suspected acid-rain problem in the West.

"But I hope we'll get him on our side," Smith adds. "The thing with Babbitt is, you always want him on your side because when it comes to negotiations, he's going to be the best-informed guy at the table, and so he's going to win."

That is the basic point about Babbitt -- on detailed policy questions, he is the "best-informed guy" because he gets so much pleasure from digging into details.

That became clear this spring to Jodie Allen, a Washington policy analyst whom Babbitt tried to hire for his presidential campaign staff.

Although Allen chose to remain in her current job -- as Washington analyst for Chrysler Corp. Chairman Lee A. Iacocca -- she says she was impressed with Babbitt's fascination with the fine points of current issues.

The interview "was just like two staffers on the Hill writing a bill," Allen says. "I would say, 'You could use a triple-matching-grant system like section 312(a),' and he would answer, 'Well, I'd rather have a section 432 tax offset instead, maybe with a double-declining differential.'

"And I thought to myself," Allen says, "my God, I'm talking to another public policy junkie."