The conservative-majority Supreme Court on Monday appeared skeptical of affirmative action in higher education during arguments over race-conscious admissions policies at two prestigious universities.

Over nearly five hours of oral argument, the justices posed sharp questions over admissions programs at the University of North Carolina (UNC) and Harvard University that consider the race of applicants — as one of many criteria — in order to achieve student body diversity.

The court’s majority appeared receptive to arguments by the conservative challengers, Students for Fair Admissions (SFFA), who argued that the schools had impermissibly weighed race in admissions decisions.

“What is your response to the simple argument that college admissions are a zero-sum game?” Justice Samuel Alito asked an attorney for a group of students backing race-conscious admissions. “And if you give a plus to a person who … falls within the category of underrepresented minority but not to somebody else, you’re disadvantaging the latter student?”

The cases heard Monday tee up the prospect that decades of affirmative action precedent could be overturned by the 6-3 conservative majority court, which last court term showed an extraordinary new willingness to scrap past rulings.

A key question heading into Monday’s arguments was how the affirmative action challenge would land with former President Trump’s three nominees — Justices Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett — none of whom have ruled on the issue as appellate judges. Those justices on Monday appeared to lean in favor of the conservative challengers, though it wasn’t clear how broadly the court’s newest members might be willing to rule.

The court’s three most senior conservatives — Chief Justice John Roberts and Justices Clarence Thomas and Alito — each of whom had opposed racial preferences in prior cases, seemed similarly wary of the colleges’ arguments.

The court’s three liberals, for their part, appeared to lean in favor of the schools’ use of race-conscious admissions. Among them was newest Justice Ketanji Brown Jackson, the nation’s first female African American justice, who participated in the UNC case but recused from the Harvard dispute due to her recent role as a member of the school’s board of overseers.