The survival of affirmative action in higher education appeared to be in serious trouble on Monday at a conservative-dominated US supreme court after hours of debate over difficult questions of race. The court is weighing challenges to admissions programs at the University of North Carolina and Harvard University that use race among many factors in seeking a diverse student body. The court’s six conservative justices all expressed doubts about the practice, while the three liberals defended the programs, which are similar to those used by many other private and public universities. Following the overturning of the half-century abortion precedent of Roe v Wade in June, the cases offer a big new test of whether the court, now dominated 6-3 by conservatives, will jolt the law to the right on another of the nation’s most contentious cultural issues. Veteran conservative Clarence Thomas, the court’s second-ever Black justice, who has a long record of opposition to affirmative action programs, noted he didn’t go to racially diverse schools. “I’ve heard the word ‘diversity’ quite a few times, and I don’t have a clue what it means,” he said at one point on Monday. At another, he challenged defenders: “Tell me what the educational benefits are.” Justice Amy Coney Barrett, another ultra-conservative, pointed to one of the court’s previous affirmative action cases and said it anticipated a halt to its use in declaring that it was “dangerous” and had to have an end point. When, she asked, is that end point? Justice Samuel Alito, who wrote the opinion that scrapped the federal rights afforded US women by Roe, likened affirmative action to a race in which a minority applicant gets to “start five yards closer to the finish line”. But the liberal Justice Sonia Sotomayor, the court’s first Hispanic justice, who joined the blistering dissent in the Dobbs v Jackson Women’s Health Organization decision that overturned Roe, rejected that comparison, saying what universities were doing was looking at students as a whole. Likewise, Justice Ketanji Brown Jackson, the court’s newest justice and its first Black woman, also said that race was being used at the University of North Carolina as part of a broad review of applicants along with 40 different factors. “They’re looking at the full person with all of these characteristics,” she said. Justice Elena Kagan called universities the “pipelines to leadership in our society” and suggested that without affirmative action minority enrollment will drop. “I thought part of what it meant to be an American and to believe in American pluralism is that actually our institutions, you know, are reflective of who we are as a people in all our variety,” she said. The supreme court has twice upheld race-conscious college admissions programs in the past 19 years, including just six years ago. But that was before the three appointees of former president Donald Trump joined the nine-member bench. After Barrett was nominated to replace the late liberal champion Ruth Bader Ginsburg shortly before the 2020 presidential election and was confirmed by the Senate, the court had a conservative supermajority. Jackson was nominated this year by Joe Biden. Lower courts have upheld the programs at both UNC and Harvard, rejecting claims that the schools discriminated against white and Asian American applicants. The cases are brought by the conservative activist Edward Blum, who also was behind an earlier affirmative action challenge against the University of Texas as well as the case that led the court in 2013 to end the use of a key provision of the landmark Voting Rights Act. Blum formed Students for Fair Admissions, which filed the lawsuits against both schools in 2014. The group argues that the US constitution forbids the use of race in college admissions and calls for overturning earlier supreme court decisions that said otherwise. UNC says its freshman class is about 65% white, 22% Asian American, 10% Black and 10% Hispanic. The numbers amount to more than 100% because some students report belonging to more than one category, a school spokesman said. White students account for just over 40% of Harvard’s freshman class, the school said. The class also is just under 28% Asian American, 14% Black and 12% Latino. A decision in the affirmative action cases is not expected before late spring.