ST. PAUL, MINN. -- Meet the high school graduating class of the year 2000, the work force of the next century, sitting cross-legged on the kindergarten floor at East Consolidated Elementary School:

In the corner is Houa Vang, 5, who, though he speaks no English, is intent on his teacher's description of water-fountain etiquette and other kindergarten rules. His Laotian Hmong family moved to this country seven years ago; he is one of six children; neither parent is employed.

Beneath a fluff of blond curls is Jessica Sellers, who is being raised by her single mother, Leah, age 22. Front row center is Juan Tijerina Jr., who lives with both parents, knows a few words of English but speaks only Spanish at home. Across the room is Sandy Leo, also 5. She is white, the daughter of a firefighter and a homemaker, has learned to read a few words and, according to her mother, will attend Catholic school next year.

At the turn of the century, if all goes well in the academic years ahead, these children will be enrolling in college or applying for jobs. By the time that happens, the country may be in for an unpleasant discovery: not only is the class of 2000 smaller than many of its predecessors, reflecting the lower birthrates of recent years, but it also could easily turn out to be less prepared for college or the workplace.

That is because the generation of students now in kindergarten, more than any before it, is dominated by children whose circumstances -- poverty, an unstable home, a non-English-speaking background, or membership in a minority group that historically has performed below average academically -- make them statistically more likely to fail in school.

"Our families do not look at all like mom and dad, two kids, a dog and a white picket fence," said principal Carol Sorenson. "There are more one-parent families, more mobility . . . . When the school opened {in 1971} there were very few minorities."

St. Paul is not afflicted with the type of urban blight found in Miami, Los Angeles, Washington or other cities. This is Middle America. East Consolidated is not a ghetto school, nor is it affluent or suburban. But it operates on the optimistic calculation that schools can close the gaps

During the current school year, a series of articles in The Washington Post will examine the challenge posed to schools and society, in the Washington area and elsewhere, by the increase in the number of "children at risk," students whose poverty, family instability or background make them likely to fail in school.

created by family background and send into the world disciplined, productive citizens.

But East Consolidated, like thousands of public schools across the country, is increasingly challenged by the children it seeks to serve. The group of students most vulnerable to failure, the troubled fringe that has always been present in public schools, has outgrown the row of desks at the rear of the room.

A group of educators recently warned that as many as a third of the nation's 40 million school-aged children are, based on their circumstances, "at risk" either of failing in school, dropping out or falling victim to crime, drugs, teen-aged pregnancy or chronic unemployment. The largest number are below school age.

The increase in the number of children likely to fail is based on a confluence of demographic factors. The proportion of children in poverty has increased from 15 to 20 percent since 1970; projections suggest that 60 percent of today's 3-year-olds will live in single-parent homes before they turn 18; immigration has increased and birthrates among poor and minority families are significantly higher than those among middle-class whites.

At the same time, the school-age population has declined, from 53 million in 1970 to 45 million last year. The city of Washington, D.C., for example, will graduate 50 percent fewer high school students in 2020 than it did in 1980, according to projections by the Educational Research Service.

The overlap of these trends has wide ramifications for society. "It used to be the case that the victim of our failure with youngsters was only the youngster," said David Hornbeck, Maryland's superintendent of schools. "Today, because we need all the kids, we all become the victim. The demographics . . . no longer permit any throw-away or disposable children."

As the number of high school graduates declines with the population, employers will be hiring from a smaller pool of applicants. They will be forced to dip further down into the ranks of young people, no longer able to bypass the lowest performers. Also, students must be better trained than in the past because a changing national economy will rely increasingly on workers able to master and adapt to new technologies.

The nation's schools, the first institution to encounter the changing demographics, are society's best -- some would argue only -- hope for solving the problem. But schools are ill-equipped to meet this heightened expectation, often hampered by limited budgets and already overburdened by immense responsibilities.

American schools have long had to cope with a group of students who fail at their studies, but traditionally, that group has been a minority, often a neglected one. But the demographic trends today indicate that many schools are moving toward a "critical mass," classrooms dominated by children at risk of failing, particularly in the nation's big cities, including Washington and some of its suburbs.

The problem is likely to touch mainstream America more than poverty has in the past. Schools in middle-class communities such as St. Paul are already feeling the impact. And, while public schools will continue to educate most of the nation's poor and troubled children, private school enrollment is changing, particularly at urban Catholic schools, which are drawing increasing numbers of minority, low-income children.

As unproductive citizens begin making up a greater proportion of the population, it will be far more difficult to address the problem of poverty through welfare and other traditional means.

"In the past, we could afford to lose part of a generation and, if necessary, it was cheaper to deal with it in terms of welfare," said Rafael Valdivieso, vice president for research at the Hispanic Policy Development Project. "Now that's changing."The Demographic Curve

Look again at the newest students at East Consolidated. Of the 167 children who enrolled in kindergarten last month, 53 live in single-parent households and 81 live in homes where either both adults are unemployed or the single parent is unemployed. For the first time this year, the minority enrollment in the kindergarten class hit 50 percent; 11 are Hispanic, 8 are black, 65 are Asian.

These kindergartners are diverse, not only in ethnic background but also in their circumstances at home and in the factors that will shape their futures. They are the children of blue-collar laborers, salesmen and secretaries, few of whom are college educated. The families of the Southeast Asian children are usually intact, but the parents unemployed, with the father often enrolled in English language courses. About half of the white children are being raised by their single mothers, several of whom, when asked to list employment, wrote "AFDC," referring to Aid to Families with Dependent Children, the federal welfare program.

The low-slung concrete school is 15 minutes from downtown St. Paul, but far from the inner city. It is surrounded by working-class homes, many of them drab clapboard, but sturdy and well-maintained. On each block are two or three dilapidated houses, some divided into apartments.

When it opened 16 years ago, the school drew the children of the close-knit Scandinavian and Italian families clustered around it. Now it draws from two public housing projects -- one occupied almost entirely by Southeast Asians -- as well as the neighborhood, whose occupants are increasingly poor and transient. In St. Paul and Minneapolis, regularly listed among America's most livable, middle-class, problem-free cities, the school-age population is gradually, inexorably changing.

It is impossible to know how many of the students at East Consolidated will drop out, but if national statistics hold true, nearly half of the students are in danger of not finishing high school by virtue of their economic circumstances.

Studies indicate that poor children are three to four times more likely than their affluent peers to leave school before graduating. Minority students are also more likely to drop out than their white classmates.

The demographic trends are clear in St. Paul, where the number of residents under the age of 20 dropped from 111,400 in 1970 to 76,231 a decade later. At the same time, minority students in the public schools increased from 11.3 percent to nearly 35 percent last year. During the 1970s, the number of female-headed households with children under 18 increased from 5,247 to 7,236 and the proportion of families earning less than $15,000 annually (in 1979 dollars) grew from 27 to 32 percent.

The trends are similar in middle-class communities across the country. In Arlington public schools, for example, the number of non-native English speakers increased from 2,947 to 4,520 over the last decade, making up 30 percent of the total student body last year. And the enrollment of Hispanic students -- who drop out of school at the rate of 14.5 percent, double that of all 16- and 17-year-olds -- climbed from 5 to 17 percent.Society Looks to Schools

At East Consolidated, the potential for failure is painfully personal and immediate.

Children walk to school on bitter, wintry days without mittens and boots. They nonchalantly tell their teachers about the violence they see at home. The parent organization that helped the school a decade ago has disappeared. The school nurse keeps a stock of milk and crackers on hand for students who have eaten no breakfast. And scrawled across dozens of enrollment forms for this year's kindergarten students are words that signal great challenge ahead: "Speaks no English."

Teaching many of these children, said Fred Johnson, a social studies teacher, "is like writing in water . . . the family or neighborhood situation blots out what happens in school. I see a certain element now we can't seem to touch, to move them off the welfare rolls."

Nevertheless, there is enough evidence of individual success at East Consolidated that teachers here continue to believe that they can overcome the deficits of poverty and family circumstance.

They point to students such as See Moua, who came to the school as a kindergartner six years ago without a word of English, a year after her Hmong family moved to this country from Laos. Now she fits comfortably in her sixth-grade class, her English is fluent and her schoolwork, executed in tiny, meticulous handwriting, is hanging on the bulletin board outside her classroom.

But the signs of failure are also abundant: schoolwide test scores come in well below national averages and teachers tell of reading newspaper accounts of former students arrested for drug dealing and prostitution. As a result, there is some skepticism about taking on even more of society's problems.

"An individual teacher can make a real difference in individual kids' lives, but I don't think the American school system can correct all the wrongs," said Mary Jo Synnott, a kindergarten teacher. "What is our purpose? Is it to educate? Is it to integrate?"

The families who bring their children here see the school as a step to a better life. As parents streamed in to enroll their children in kindergarten last month, many with the help of Hmong and Spanish interpreters, there was nothing in the conversations to acknowledge that the years ahead may bring disappointment.

"I want her to finish through the 12th grade," said Leah Sellers of her daughter, Jessica. "I didn't quite make it, so I want her to."

Jessica was born when her mother was a teen-ager. Now Leah Sellers is raising Jessica and her younger brother on her own while she does clerical work at her father's machine shop.

Janise Chumley, a nurse's aide, gave her daughter Keviann a similar message when she brought her in on the first day of school: "I hope you'll be enthused to go to school like you are today for the next 13 years, and then some."

But it is apparent when parents line up to register and the buses spill out at the school doors that the accumulation of all these special needs could overwhelm the school. Of 995 students, about half receive free lunches because they come from low-income families, a third receive compensatory education in reading or math and about 200 get extra tutoring because English is not their primary language.

The most dramatic change in the school's enrollment has been an influx of Southeast Asian families, mostly Hmong tribe refugees from Laos sponsored by church organizations in the Twin Cities.

Houa Vang, whose family was among 6,000 Southeast Asian refugees who arrived in the city between 1970 and 1980, is typical. He must meet the challenges of a foreign country whose language he does not know, the economic hardship of unemployed parents and a childhood raised in a housing project.

"I try to teach them to speak English, but at home, they speak Hmong," said Houa's father, Kao, who is taking language courses. Houa, he said, "cannot speak any English. He's so serious. He doesn't like to talk to adults."

It is here in the classroom that the great expectations of society have come to rest. As in the past, when the country focused on correcting racial and economic inequalities, most of the solutions proposed today lie with the public schools.

"It's a demographic given that if we don't do anything new, it's going to get worse," said Harold L. Hodgkinson, a senior fellow at the American Council on Education. "The educational system is the only system left that seems to function in a way that we can get a handle on it. The family, church . . . all have gone through striking changes."

But for the most part, schools are ill-prepared to handle the task. Despite the improvements ushered in with the education reform movement of the past few years, classrooms are still often crowded and resources limited. And many educators have argued that the reform movement may be exacerbating the problems of poor performers by raising graduation requirements without adding instructional help.School Role Expanded

Underlying the new expectation is an assumption that the schools can act as socializer, imbuing in students the moral and behavioral lessons historically left to the home. But this comes after numerous other mandates, from driver's training to drug prevention, have already expanded the schools' traditional role as educator.

While schools such as East Consolidated are well aware of the demographics, many school officials and government leaders have been slow to respond to the situation, according to Hodgkinson, National Education Association President Mary Hatwood Futrell and other leaders in education.

"The American people have not accepted this as a major concern," Futrell said earlier this year. "Until it becomes a national priority, we'll plod along as we are today."

But in an educational environment where apocalyptic pronouncements are common (warnings about drug abuse last year followed similar statements about illiteracy and teen-aged pregnancy), Hodgkinson's arguments are sometimes greeted with skepticism. Critics argue that children can often overcome one problem and it is only those facing several disadvantages who are likely to fail.

Hodgkinson responds that the demographics are clear. "These kids are simply going to grow up," he said. "It's the only group of kids we have."

At East Consolidated, teachers and administrators do not have a sense of being overwhelmed by students suffering the consequences of poverty. There are still plenty of middle-class children in the school, but as the number of poor students increases, the trend creates its own momentum.

Jane and Frank Leo registered their daughter, Sandy, for kindergarten because they wanted a half-day program. But when Sandy is ready for first grade, they said, she will go down the street to the parochial school their three older children have attended.

Jane Leo said she preferred the more structured atmosphere at the Catholic school. "Plus, these are not the best neighborhoods," she said. "I'm not talking about color, but the kids are picking up rotten habits, plus they have no respect for authority."

In response to the changing enrollment, the staff at East Consolidated has taken on new responsibilities and the school has redefined its mission, much of it embracing the role of socializer.

In the first week of school, staff member Joe Haller drove around the neighborhood in his maroon Ford, making what the staff calls "home visits."

At one house, he stood on a steep, disintegrating apartment stairwell and carefully explained to a mother what she needed to do to enroll her child in kindergarten. The family already has three children in the school and the staff knew that a fourth was ready to attend kindergarten, but the mother did not show up for registration.

"The bus will pick him up on the corner," Haller said to the mother. "Now you need to sign this and get his shots, then return this form to school. This envelope is for milk money."

"You'll have to wait until Thursday," the mother said. "That's when I get paid."

The school has adapted in numerous other ways. It offers a "changing families" curriculum, open to children who want to talk about divorce, death or alcoholism. There is a "parent outreach" program, to help parents work with children at home, including those who are too young for school.

But the academic fate of most children will be decided not by special programs, but in the regular classroom. Teachers have already changed their routines to incorporate a wide range of abilities. Synnott speaks to her class with broad, animated gestures aimed at children who don't understand English. She teaches at a slower pace than she used to, she said, assuming that parents will not reinforce the lessons at home. And she no longer expects that children will know the basics, even how to use kitchen utensils or the bathroom.Predicting Failures

Despite the willingness of teachers to adapt, the challenge facing the school is obvious, even on the first day.

Many students arrive late and have already lost the name tags they were given at registration the day before. Small circles of Hmong children gather in the corners, speaking their native language to each other. While some children are reading first-grade books, others are struggling to put together puzzles designed for toddlers.

Pat Allen, who has taught at the school since 1974, said that within a few months, she can predict pretty well who among these children is going to succeed and who will fail. "You can do it," she said. "It's kind of scary."

As the children gathered in groups around her, she added, quietly: "Some will do okay, some won't finish . . . . A lot are headed for trouble."