(FORTUNE Magazine) – ROSEMARY is a lovely girl, but your mother and I are a little worried. We certainly don't want any Catholic grandchildren.'' So Pulitzer Prize Committee Chairman Robert C. Christopher's father told him in a serious paternal chat about a beautiful Irish girl over 40 years ago. But now the elder Christopher has grandchildren who are half-Jewish, and he will have half-Chinese great- grandchildren. Says Christopher: ''He's relaxed about it.'' That change of heart isn't just personal; it sums up a momentous revolution in American attitudes and society. Decades in the making but accomplished with inexorable force over only the past ten or 15 years, that revolution advances by a giant step the American ideal of an open society in which people are accepted and rewarded for their own merit, talent, or hard work rather than for the accident of their birth. For all their vastness, changes that take place quietly over a long period are hard to perceive as they occur. One aspect of the new American openness -- the wholesale movement of Jews, Catholics, women, and others into seats of prominence and authority hitherto occupied largely by male WASPs -- jumps sharply into focus in a new book by Robert Christopher, Crashing the Gates: The De-WASPing of America's Power Elite (Simon & Schuster). And even as this book celebrates the rise of groups formerly poor and outside the mainstream, the sometimes spectacular success of America's latest wave of immigrants testifies that opportunity is even more open than earlier groups found it. Despite the democratic traditions of this nation of immigrants, American society wasn't always wide open. Remember Groucho Marx's funny but wistful plea to the swim club that refused membership to his children: Since they were only half-Jewish, he wondered, perhaps they could be allowed in up to their navels? In the Twenties, with stiff Jewish quotas the norm at Ivy League colleges, Jewish students at Harvard had to sit in a special, segregated corner if they attended the Freshman Jubilee dance or the senior prom. Across the river in Boston at the same time, Irish visitors to grand houses were expected to use the back door. Father Andrew Greeley remembers an Irish businessman in Boston in the Fifties whose WASP colleagues, convivial enough at lunch, would not invite him to their homes or introduce him to their wives. As recently as John Kennedy's 1960 campaign, it wasn't clear that a Catholic could aspire to be President. Early in this century the California legislature made the state's many Chinese and Japanese immigrants ineligible for citizenship and denied them such basic civil rights as owning land or giving testimony in court. Carl Spielvogel, chairman of the Backer Spielvogel Bates Worldwide advertising agency, recalls when background and connections, as much as talent, counted for success in his industry, as in others. ''In 1960 advertising was still a white-shoe business,'' he says. ''School, school tie, and the team that you played on all meant a lot.'' Non-WASPs in advertising as in other businesses often assumed WASP-sounding names, WASP manners, and WASP tailoring and hoped no one would guess. Such realities -- frustrating and painful at the time -- might seem to younger readers as remote as the minuet or the pillory. Today when a Greek- American runs for President, many political pros consider his ethnicity an advantage, and Italian Catholic Geraldine Ferraro found her religion and ethnicity no hindrance in campaigning for the vice presidency. Part of the fascination of Robert Christopher's book is his listing of non-WASPs now established in seats of power. For instance: Adams, Boschwitz, Cohen, D'Amato, DeConcini, Durenberger, Inouye, Kassebaum, Kerry, Lautenburg, Leahy, Levin, Matsunaga, Mikulski, Murkowski, Sarbanes -- the roster, Christopher remarks, reads like a Hollywood-style army squad in a World War II movie but is in fact a list of U.S. Senators. Blacks run two of the nation's top nonprofit organizations -- Franklin Thomas at the Ford Foundation and Clifton Wharton at TIAA-CREF, the giant teachers' pension fund -- and Steven Minter, also a black, heads the prestigious Cleveland Foundation in a town where racial and ethnic barriers until recently were rigid. At the hyper-Establishment Council on Foreign Relations, Greek-American investment banker Peter Peterson serves as chairman, and Peter Tarnoff, who is Jewish, is president. THE TOP EXECUTIVE RANKS of big corporations have similarly opened up to talented non-WASPs, especially Catholics. Two surveys by the Korn Ferry headhunting firm of 4,350 big-company executives just under the CEO level show how rapid and recent the change has been. In 1979, 68% of the executives were Protestants and 22% were Catholics; but in 1986, 58% were Protestants and 27% were Catholics. Say ''big business'' today, and the first face that pops into the average American's mind is likely to be Lido Iacocca's. The extraordinary success of Jewish-Americans plays an important part in the story of American openness in this century. For most Jewish-Americans of East European descent, that story begins in crowded urban poverty at the turn of the century, when 67% of Polish-Jewish schoolchildren in major northern cities tested as ''retarded.'' Their success in America should be seen as a proof and a promise to the many recent Asian, Cuban, Dominican, Greek, Indian, Irish, Haitian, and other immigrants of how open to their efforts American society really is. At the major corporate law firms on Wall Street and in Washington, D.C., for example, Smith College political scientist Stanley Rothman found that 15% of 150 partners were Catholics and 41% were Jews. So astounded was Rothman by the latter figure, especially since the firms he surveyed didn't include those that used to be thought of as ''Jewish,'' that he went back and reconfirmed his results. And in the snootier reaches of the elite world, almost a quarter of the members of the prestigious board of New York's Metropolitan Museum of Art, for example, are Jewish. The ultimate measure of the nation's social openness, beyond the permeability of its elites, is the intermarriage rate, which shows the degree to which people are willing not just to hire and promote but to marry across ethnic barriers. It is startling. In the 1980 census data, the latest available, Harvard sociologists Stanley Lieberson and Mary Waters found a striking decline in the degree to which people of the same ethnic ancestry marry each other (see graph). For example, while only 44% of married people of Italian ancestry who were 65 or older had married non-Italians, 77% of those under 25 had. Among Jews, 70% of those surveyed in Boston in 1965 opposed intermarriage for their children, but only 34% opposed it ten years later. Of non-Jews under age 30 surveyed nationwide in 1975, only 4% professed disapproval of intermarriage with Jews. By 1981 a third of third-generation Japanese-Americans were marrying Caucasians, and the number of Asian-Caucasian marriages increased 70% between 1976 and 1986, leading some social scientists to foresee a substantial Eurasian component in the American middle class in the not very distant future. WHAT FORCES brought about the new American openness? As a watershed, Christopher points to the G.I. Bill, which after World War II gave a college education to thousands who otherwise would never have dreamed of higher education. The result was to swell the ranks of the trained and make the ambitious look higher. The ground had been laid far before that by the progressive effort to replace the patronage of corrupt machine politics with objective merit and so reaffirm America's original commitment to the key liberal idea of the career open to talents. In the business world increased competition over the past 15 years has forced greater opening. Financial deregulation, global competition, and the discipline of raiders and restructuring have all raised the premium on talent | and a mastery of the business rather than that on relationships. The WASPocracy didn't have power wrested away from it, but voluntarily dispersed it. According to University of Pennsylvania sociologist E. Digby Baltzell, the WASPs waited too long to make this concession. Instead of routinely coopting gifted outsiders into their ranks, American WASPs kept their society closed and became a caste rather than a vital aristocracy. By the time the WASPs ceded power, they and their values were enfeebled. Their new openness is part of a general ''anything goes'' mentality. Says Baltzell: ''Nobody bothers to make any distinctions anyway, so what the hell?'' From a different point of view, Commentary editor Norman Podhoretz believes that the WASP elite has suffered a loss of confidence since the Sixties, a loss that author Christopher attributes to the failure of the primarily WASP best and brightest in directing the Vietnam war. One can argue about the timing, but says former Harvard University dean Henry Rosovsky: ''I admire the way the WASPs opened up their institutions. They did it out of a moral sense rather than being pushed into doing it. They felt it was important for the society.'' And sometimes they did it with panache, as when Berkshire Hathaway Chairman Warren Buffett encouraged Omaha's premier country club to drop its WASPs-only policy by joining the Jewish club instead, mildly observing that its food was better. By now it is a truism that the success of America's most recent immigrants shows how breathtakingly open the society really is to ambition, hard work, and self-help. Think of the 2,800 Korean-owned businesses in Los Angeles, with schoolchildren diligently doing their homework behind the counters, or the 25,000 Cuban-owned businesses, from mom and pop stores to two major banks, in the Miami area. Think of Asians and Hispanics moving steadily out of immigrant neighborhoods into the general population as their incomes and levels of education rise. It almost seems as if such success were easy. It is not. Taking advantage of the opportunities of the open socity is a years-long struggle that commands respect. It also exacts costs, as it has from immigrants of every generation. HARD WORK goes without saying. Acclaimed Chinese-American novelist Amy Tan tells of her half-sister and brother-in-law, both 50-ish, who arrived from China only six years ago. After four years they owned a car, three televisions, a house. They have two children in college. Since they have what ( some call ''dead-end jobs'' -- she helps run a restaurant in Chinatown and he works as a dish washer -- they paid for these things by working constantly, six days a week with no vacations, and by unwavering frugality and thrift. ''These things were important to them,'' says Tan, ''as a sign that they had succeeded and that they had taken advantage of an opportunity they wouldn't have in China.'' They gave up a lot for that opportunity: He was a surgeon in China, she a nurse. Explains Tan: ''My sister said, 'We came for the children. I know I'll never get ahead that far. I'm working hard. We're doing fine. But it's my children who are going to do well, for us.' '' And so among Chinese immigrant families, says Tan, the children take on the responsibility of working hard to achieve their parents' goals. They prosper and assimilate. Says Tan: ''That's what American society sees. What they don't see is that the immigrants who come to this country as adults do not assimilate as well as people think.'' After six years Tan's sister still doesn't speak English. A friend who has been in America ten years similarly hasn't learned English, and, since she knows only one way to get home, she directed Tan ten miles out of the way to drive her there. Says Tan: ''That to me was a perfect metaphor for her lack of assimilation.'' Outsiders also can't perceive the emotional costs. The responsibility of achieving their parents' goals can seem a burden to children. And as with previous immigrant groups, today's immigrant parents experience their children's assimilation as both a fulfillment of their own ambitions and as a betrayal. In becoming American, the children become less . . . Chinese, Mexican, Jewish -- fill in the blank. And so, parents fear, the children become less able to understand the values that support the parents' sense of their own worth. WORSE IS THE FEAR that all American parents of the Eighties share. Says Frank Cho, head of the Korean-American Garment Industry Association in Los Angeles: ''American schoolchildren are not well-disciplined. They can do whatever they want. I mean, they can hit or shoot -- it's entirely beyond our imagination. Another thing is those bad habits, narcotics. It's maybe too liberated or free for anyone to have access to those kinds of things. A lot of Korean parents are worried about their children being addicted to them, and some already are.'' American openness presents much the same chance to all newcomers, but . different groups of immigrants have achieved different degrees of success depending on what they have brought to their opportunities. A leavening of the entrepreneurial spirit, for example, has helped make Asians and Cubans the most successful of recent immigrants. Many live in self-contained, mutually supportive, virtually self-sufficient communities -- so-called enclave economies, networks of immigrant-owned businesses that buy and sell to each other and employ a significant portion of a given immigrant group. Employees, whose lack of English limits their job choices outside the enclave, often start with dirty jobs and work long hours for low wages. In return, employers are quick to promote them and often to help them if they set up businesses of their own. Sociologist Alejandro Portes of Johns Hopkins found that the usual route to starting their own businesses among Cuban refugees he studies was first working for a Cuban firm. ''It's a kind of informal business school,'' he says. By contrast, Mexicans, the largest recent immigrant group, are succeeding more slowly, though succeeding nevertheless. Mainly unskilled laborers without an entrepreneurial tradition, they largely have remained working class. New arrivals have found no network of welcoming employers, making lack of English a far greater hindrance for them than for Cuban immigrants. The key to their economic achievement, according to several studies, appears to be learning English, so that bilingual education, instead of making the society more open to their children, probably keeps it more closed. Immigrants from the Caribbean are making it too -- except for significant numbers of Puerto Ricans. Linda Chavez, former staff director of the U.S. Civil Rights Commission, attributes the lack of success to welfare, deeply entrenched in Puerto Rico as well as in mainland Puerto Rican communities and offering a viable if deplorable alternative to low-wage work. The result is that Puerto Ricans are being shunted aside by newer Hispanic immigrants, to whom American opportunity looks good by comparison with the situations they've left. THE UNHAPPY EXAMPLE of closedness in American society has been the case of black Americans, so long excluded from full participation by barriers first of law and then of custom. But even here obstructions have crumbled and opportunities opened with amazing speed over the past three decades. As one luminous gauge of success, the number of black families below the poverty line declined by 5% between 1981 and 1986, while the real median income of black families rose 10%. But success has entailed a paradoxical byproduct. As the majority of blacks rose and prospered, they fled urban ghettos for neighborhoods newly open to them, leaving behind in the inner cities an increasingly concentrated, isolated residue of the unsuccessful, who became the main component of the urban underclass. Reasonable thinkers differ on the precise pathology that created their plight, but it seems most likely that the welfare system designed to help them instead made them dependent, and a culture of poverty, which rejected the values it takes to rise out of poverty, made them emotionally and educationally unable to seize opportunities that were increasingly open. What seems unlikely, however, is that the existence of an underclass shows that America is not an open society.

Says prizewinning essayist Shelby Steele, a San Jose State College English professor who is black and who writes thoughtfully and compassionately about the condition of American blacks: ''I think it takes a certain set of values and attitudes to be able to take advantage of opportunity, and those values are probably missing or undeveloped in the black underclass.'' Part of the problem, Steele believes, is a preoccupation with victimization and an overpowering resentment. Says he: ''Black national leaders have reconvinced blacks that they're victimized. They focus on racism rather than point out to blacks their opportunities and the kinds of values it takes to exploit them.'' Worse, he believes, an emotional double bind entraps not just underclass blacks but even some members of the black middle class. Minority groups have always felt ambivalent about joining the American mainstream because they have feared they would lose a portion of their original identity. Still, they have entered fully. But among blacks the ambivalence sometimes seems even stronger, more lopsided, more incapacitating. Explains Steele: ''The kind of black identity that emerged in the Sixties was focused around victimization: The proud black man was basically a poor, ghettoized black person. And so black middle-class people, in order to achieve their identity, had to identify with that, even though it was a contradiction to the reality of their lives, their aspirations, their opportunities. That tension held the black middle class back. You may be middle class, but if you're encouraging your children to be / black and identify with the mass of black people, you're conditioning them to be poor, to not subscribe to the same values that you yourself are living by.'' Little wonder, says Steele, that such children sometimes fall out of the middle class. After enormous progress, the barriers that most hinder social mobility in America today are in the minds of citizens, not in the society at large. The right message for all is: Most doors are wide open in America now. He may walk through who will.

CHART: NOT AVAILABLE CREDIT: SOURCE: FROM MANY STRANDS BY STANLEY LIEBERSON AND MARY C. WATERS CAPTION: LEAVING THE FOLD