Although he is the first Mexican-American mayor of San Antonio since the days of the Texas Republic and the first in a major American city in modern times, Henry Cisneros has drawn attention as a minority politician of a different stripe:

He is an apostle of high technology who preaches the gospel of economic development, not the causes of civil rights or the power of government social programs.

Just 35, he is running at a whirlwind pace. There are meetings at the White House, speeches in cities from New York to Los Angeles, interviews with columnists and television networks and private sessions with Democratic presidential aspirants.

In nearly two years as mayor he has generated superlatives more rapidly than a utility produces power, and his high-voltage style has prompted enough speculation about his future to humble even the most immodest politician.

But, in fundamental ways, the world envisioned by Cisneros when he was elected has changed, and he is being forced to reconsider whether his skillful political balancing act is still appropriate.

A favorite of the White House, he is weighing the cost of becoming its critic. And at home, although immensely popular, he has yet to deliver fully on expectations he aroused.

So this is a particularly difficult time for a man accustomed to charming opponents and succeeding at nearly everthing he tries.

With the national economy running against him and some fellow Democrats suspicious of his motives, Cisneros' handling of this transition period may tell more about his political talents than does the stack of glowing press clippings he has assembled.

Cisneros may have been bred to run a city. His maternal grandfather came to San Antonio from Mexico in the 1920s and entered the newspaper business.

His father was an Army colonel and, while Cisneros did not exactly follow in his father's footsteps, he enrolled at Texas A&M University at a time when being in the cadet corps was mandatory. He left as a distinguished military graduate.

He went to Harvard for a master's degree in urban studies and earned a Ph.D. at George Washington University. He was an assistant city manager in two cities and worked in the Model Cities program in San Antonio.

He also spent two years as a White House fellow, working for Elliott L. Richardson, the durable Republican jack-of-all-trades in the Nixon and Ford administrations.

Cisneros returned to San Antonio in 1974 as a professor at the University of Texas at San Antonio and dived into local politics, winning election to the City Council on the establishment slate in 1975.

He later allied himself with Mayor Lila Cockrell and began to carve out economic development as his area of expertise. When Cockrell decided not to seek reelection in 1981, Cisneros won 62 percent of the vote against a well-established opponent.

"I like to think I know the city business," he said in a recent interview. "This is something I've trained for, this is something I came up in. The city business."

Cisneros once said, "There is no alternative to trickle-down economics." That was in April, 1981, a few days before his election. President Reagan was riding the momentum of his 1980 victory over Jimmy Carter, and big-government Democrats were wondering if they might soon become the minority party.

Cisneros' skepticism about big government and his devotion to economic growth made him an immediate favorite of the Reagan White House, eager not only to attract Mexican-American votes but also to find Democratic mayors not instantly hostile to administration budget cuts.

Ever reasonable and nonpartisan in sessions at the White House, Cisneros became a welcome visitor in Reagan's Washington.

"Obviously we'd prefer that he be a Republican, but he's been pretty good on free enterprise," said Richard Williamson, assistant to the president for intergovermental affairs. "He's constructive . . . rather than Mau-Mauing."

When elected, Cisneros had an enticing vision for his city, which then had a somewhat outdated reputation as a charming Latin tourist town.

He looked at the crumbling cities of the Northeast and Midwest, with auto and steel plants idled by foreign competition and obsolete machinery, and realized that a fundamental change in the U.S. economy was under way.

He looked toward Mexico, then in the early stages of what looked like a period of unprecedented economic expansion, and saw great opportunities.

Cisneros decided that San Antonio must not be bypassed by the high-technology revolution brewing across the Southwest, that it could also be a launching pad for U.S. companies seeking to strike it rich in Mexico, that it should be the economic hub for south Texas.

He believed that, in doing all that, he could help to bring prosperity to the browns and blacks of San Antonio.

"I concluded that for south Texas and San Antonio, economic development was the only way to raise the incomes of poor people," he said in the spring of 1981.

He became a salesman for San Antonio, the chief recruiter of new industry, a classy symbol of a community that had overcome racial divisions to become a city on the make.

"I think he is just the answer to what this community needs, and perhaps a few other communities," said Tom Frost, one of the town's leading bankers.

Cisneros launched an ambitious program and buried himself in details of high tech, mastering the language of robotics, fiber optics and embedded computer systems and a whole world of arcane machinery that he saw as part of his city's economic salvation. At night and on airplanes as he flew to speeches and meetings, he produced a 242-page blueprint for the city's place in a high-tech society. But he understood that the high-tech revolution threatened the future of the cities as much as it promised salvation.

"There are horrible, frightening issues in there for poor people," said the mayor of a city more than 50 percent Hispanic. "I think it holds great promise, but there is an underside to it that nobody is thinking about."

He faulted the so-called "Atari" Democrats for placing too much emphasis on the promise of high tech without recognizing the costs.

"I don't think they're dealing with the equity issues enough," he said. "One could envision it succeeding, and we'd have a boom economy -- and we'd still have central-city poverty."

To prepare his own city, he helped bring an engineering curriculum to the University of Texas at San Antonio and promoted the idea of a high-tech high school to train youngsters for the economy of the future.

He argued that colleges in south Texas deserve a larger share of research money available to state schools.

In addition to high tech, his program included 12 binders filled with the details of every major project or idea in city hall: downtown development, drainage, energy, crime, historic preservation and neighborhoods. There was even a file called "letters to authors," which included results of a recent meeting with James Michener, who is writing a novel about Texas. Cisneros is encouraging Michener to use San Antonio as a fictitious setting for the book.

Articulate, urbane, energetic, Cisneros quickly became prominent among fellow mayors. Wall Street loved him, too, and in the face of the recession the city's bond rating improved.

At home, Cisneros was not without critics, who said he was too cozy with bankers and developers at the expense of brown and black citizens.

"People approach me and say, 'Oh, that Cisneros made such a beautiful speech,' and then I have to fight him on all the things that are important to Hispanics," said City Council member Bernardo Eureste, a friend and political rival of Cisneros. "On almost anything that is a liberal cause, Henry is in the way."

Said Sonia Hernandez, president of San Antonio Communities Organized for Public Service, an adversarial neighborhood organization, "At this point, he's been more hype than substance."

But that was not the majority viewpoint recently summed up by Council member Van Archer, who managed Reagan's south Texas campaign in 1976 and 1980. "He's the right man at the right time," Archer said. "He's youthful, he's a young man in a hurry. He exudes confidence. I think he is a very, very good mayor."

When Cisneros ran for mayor, he pledged to a Republican organization that he would be nonpartisan, continuing the tradition of his predecessors.

At the time, that seemed to make good sense: the country was riding a conservative wave, the White House was in Republican hands, and the governorship of Texas was held by a Republican for the first time in 105 years.

So, as Texas Democrats began their most united fight in memory to recapture the governor's office, Cisneros, a Democrat with political ambitions, stood on the sidelines.

"I did what I had to do," he said later. "But I didn't like it."

Neither did some Democrats. On the morning after the 1982 election, in which the entire Democratic ticket was swept into office, telegrams began arriving at the campaign headquarters. They said, "Congratulations on your major victory," and were signed "Mayor Henry Cisneros."

The irony was not lost on some of the people who had worked hardest for that victory. Said one Democrat at the time, "Henry needs to be a good Democrat and pay some dues. There is a need to do a rehabilitation program."

The elections reminded some people that they distrusted the smooth and charming Cisneros, that they felt he had been too eager to please the White House, too enthusiastic about economic growth at seemingly any price, too willing to remain above the fray.

In fact, Cisneros had become something of a super bureaucrat on urban affairs, an expert on "the city business," a sought-after speaker whose scholarly lectures on city problems were well received by even the most cynical audiences.

He was also the nation's most visible Hispanic politician. But to critics he was a Democratic politician unwilling to offend Reagan Republicans.

Cisneros is defensive about his style, and says his decision to stay out of partisan politics was in San Antonio's interests. "Let's just talk about what it means for me to withdraw from the mainstream of partisan politics and play this role . . . ," he said recently.

"A series of expectations that people built for me over the last few years that I would either be involved in statewide politics or that I was angling for some sort of high appointment, I bypass, and consciously so. That ought to speak volumes about this so-called young man who was supposed to be more ambitious for himself and was using San Antonio as a steppingstone."

But another thing began to register on Cisneros during this period. As long as the recession continued, his dreams of economic revitalization for San Antonio would never be fulfilled.

Mexico's economy had all but collapsed, closing off that avenue. Despite an aggressive industrial recruitment campaign, San Antonio lost manufacturing jobs because of the nationwide slump. The city's unemployment rate, while below the national average, was 7.3 percent in October, compared with 5.6 percent when Cisneros was elected.

Cisneros concluded that Reagan administration economic policies were tearing the country apart and that drastic remedies were needed to revitalize the economy.

Stung by criticism of his role in the fall campaigns, he began moving toward an adversarial position with the Reagan administration.

"The Reagan approach is just too cruel and is going to hurt the country in the long run," Cisneros said. "I just think the administration is blind to the plight of many parts of the country. Just blind."

He is now deciding whether he should use the prominence he has gained in two years to launch a more public attack on administration policies.

In April, Cisneros will run for reelection, and at the moment he appears to have no strong opponent.

But beyond are the 1984 national elections and the question of his involvement in what will again be a critical year for the Democratic Party. Cisneros says that will be determined by his performance in San Antonio.

"What we're driving at," he said, "is creation of a model that proves that an ethnically diverse city with a large number of poor people -- most of whom have been undereducated -- can succeed in this system, can not only create a city that works but a city that provides jobs and opportunities for people. That hasn't been done.

"Name another city in the top 10 with 60 percent minority population that is trying to do some of the things we're trying to do. If American cities can't do that, we're . . . doomed to the backwaters of American society. If they can , we've got a system we can sell to the world. Those are really the choices."

Cisneros remains confident of his own talents. "I need a couple of breaks," he said. "I need a break from the national economy. It's lousy. But on every other count I think we'll succeed."