BOSTON — For generations, being the child of a Harvard graduate has held out the tantalizing promise of an admissions advantage, a leg up over other applicants who had no Harvard ties.

Now the plaintiffs at a trial in federal court here are calling for the elimination of that preference for alumni children, who are predominantly white and wealthy.

The so-called legacy preference became the focal point of testimony this week, as witnesses discussed whether there were ways to maintain ethnic diversity at Harvard without considering the race of applicants. The plaintiffs, who accuse the university of discriminating against Asian-Americans, proposed several “race-neutral alternatives” that Harvard could use to keep its classes diverse. Harvard said these alternatives would not work.

One of the proposals was to eliminate preferences for legacies, or the children of alumni. By giving preference to wealthy white legacies, the plaintiffs say Harvard has been squeezing out everyone else, mainly high-achieving Asian-American applicants. Harvard denies discriminating against these students.

The plaintiffs’ expert witness, Richard Kahlenberg, a senior fellow at the Century Foundation, recommended that Harvard instead give a stronger preference than it does now to low-income students from across the country.

He also proposed getting rid of admissions advantages for the children of faculty and staff; students from families on the Dean’s and Director’s interest lists, who are often major donors; and students on the Z-list, a back door for those who are not as qualified as most of their peers and are asked to defer admission.

Mr. Kahlenberg said he would preserve the preference for recruited athletes, who are mostly white at Harvard, because eliminating it would have too “radical” an impact on college athletics.

Doing all of this, Mr. Kahlenberg said, would keep classes diverse while throwing out admissions preferences that the plaintiffs perceive to be unfair.

Harvard’s witnesses, a dean and a former dean, strongly rejected the idea that socioeconomic factors alone could substitute for race. They said that the proposal advanced by the plaintiffs would lead to an unacceptable decline in the percentage of black students.

Michael Smith, the former dean of the faculty of arts and sciences, testified that under Mr. Kahlenberg’s proposal, Harvard would lose the academic cream of the crop: The proportion of admitted students with the highest academic ratings would drop to 66 percent, from 76 percent.

The university would be “going backwards from where we are today,” Mr. Smith said.

Mr. Kahlenberg said the difference in academic qualifications would be minuscule, and could be overcome by students who had already overcome obstacles like poverty and inferior schools.

Under the plaintiffs’ proposal, which uses data from the class admitted in 2015, the proportion of students the admissions office would consider “disadvantaged” would rise to half the class, from the current 18 percent.

The share of white students admitted would drop to 32 percent from 40 percent, mostly because of the elimination of legacy and other preferences. The Asian-American share of the class would rise to 31 percent from 24 percent, and the share of “Hispanic and other admits” would also go up to 20 percent from 14 percent.

But the African-American share would decline, to 10 percent from 14 percent.

Harvard said that was a key reason that it would not make its admissions process race neutral.

The university’s witnesses also said it was necessary to preserve the legacy advantage because it helped encourage Harvard alumni to volunteer and donate. Many alumni recruit and interview prospective students in the hope that their efforts will be noticed and rewarded by Harvard when their own children apply.

Rakesh Khurana, dean of the college, said the change in the composition of the class wrought by the plaintiffs’ proposal would make going to Harvard a much different experience.

Harvard fosters the ability to “see the world from somebody else’s perspective,” Mr. Khurana said.

He said that as a residential dean at Cabot House, living among undergraduates, he had seen students from different backgrounds come together in the dining hall and library, form friendships that would last a lifetime and even “fall in love.” That understanding, he said, was as important as anything that came from books and classes.

Mr. Kahlenberg acknowledged that Harvard had been doing “a very good job” at building a racially and ethnically diverse class.

But he said it had not done such a good job at admitting students who had managed to excel academically despite poverty.

Harvard now has “23 times as many rich kids as poor kids,” Mr. Kahlenberg testified.

He said that his model could be improved by taking into account family wealth, as well as income. A wealth measure would help increase the admission of African-Americans, he said, because while their income is 60 or 70 percent that of whites, their family wealth is much lower because of generations of discrimination.

To bolster his case, Mr. Kahlenberg quoted President Barack Obama, who once said that his two daughters should not be given preferential treatment in college admissions because they came from privileged backgrounds.

The question of whether there are race-neutral alternatives to Harvard’s admissions policies could become more important if the case makes it to the Supreme Court. Past Supreme Court precedent has cited Harvard’s admissions system as a model for achieving diversity. But it has also ruled that colleges cannot consider applicants’ race “unless no workable race-neutral alternatives would produce the educational benefits for diversity.”

Finding a viable alternative could transform affirmative action as it is known today.

Mr. Kahlenberg said that Harvard was a laggard among elite universities in ending legacy admissions. Venerable universities — Oxford; Cambridge; the University of California, Berkeley; and the California Institute of Technology — do not have legacy admissions, he said.

Mr. Khurana said he was not ruling out any changes to admissions practices. But, he added, “at present we couldn’t identify a race-neutral alternative that met our overall institutional objectives.”

First Published: October 24, 2018, 7:00 a.m.