PROFESSOR Becker, a celebrated free-market conservative, wrote his Ph.D. dissertation (and first book, “The Economics of Discrimination”) to demonstrate that racial discrimination was economically inefficient. American business leaders seem to have learned that there is no money to be made in exclusion: bringing in each new group has simply created new consumers to court. If you can capture nearly three-quarters of the economy’s growth — as the top 1 percent did between 2002 and 2006 — it may not be worth worrying about gay marriage or skin color.

“I think we have become more meritocratic — educational attainment has become increasingly predictive of economic success,” Professor Becker said. But with educational attainment going increasingly to the children of the affluent and educated, we appear to be developing a self-perpetuating elite that reaps a greater and greater share of financial rewards. It is a hard-working elite, and more diverse than the old white male Anglo-Saxon establishment — but nonetheless claims a larger share of the national income than was the case 50 years ago, when blacks, Jews and women were largely shut out of powerful institutions.

Inequality and inclusion are both as American as apple pie, says Jerome Karabel, a professor of sociology at the University of California, Berkeley, and author of “The Chosen,” about the history of admission to Harvard, Yale and Princeton. “I don’t think any advanced democracy is as obsessed with equality of opportunity or as relatively unconcerned with equality of condition,” he says. “As long as everyone has a chance to compete, we shouldn’t worry about equality. Equality of condition is seen as undesirable, even un-American.”

The long history of racial discrimination represented an embarrassing contradiction — and a serious threat — to our national story of equal opportunity. With Jim Crow laws firmly in place it was hard to seriously argue that everyone had an equal chance. Civil rights leaders like the Rev. Dr. Martin Luther King Jr. were able to use this tradition to draw support to their causes. “Given our culture of equality of opportunity, these kinds of rights-based arguments are almost impossible to refute,” Professor Karabel said. “Even in today’s conservative political climate, opponents of gay rights are losing ground.”

The removal of traditional barriers opened up the American system. In 1951 blacks made up less than 1 percent of the students at America’s Ivy League colleges. Today they make up about 8 percent. At the same time, America’s elite universities are increasingly the provinces of the well-to-do. “Looking at the data, you see that the freshman class of our top colleges are more and more made up of the children of upper- and upper-middle-class families,” said Thomas J. Espenshade of Princeton, a sociologist.

Even the minority students are more affluent, he noted; many of them are of mixed race, or the children of immigrants or those who benefited from affirmative action.