Supreme Court justices sharply questioned the University of Texas' use of race in college admissions Wednesday in a case that could lead to new limits on affirmative action.

The court heard arguments in a challenge to the program from a white Texan who contends she was discriminated against when the university did not offer her a spot in 2008.

The court's conservatives cast doubt on the program that uses race as one among many factors in admitting about a quarter of the university's incoming freshmen. The liberal justices appeared more supportive of the effort.

Justice Anthony Kennedy, whose vote could be decisive, looked skeptically on Texas' defense of the program. "What you're saying is what counts is race above all," Kennedy said. He has never voted in favor of an affirmative action program but has voiced support for diversity in education.

Twenty-two-year-old Abigail Fisher, the rejected student who sued, was among the hundreds of spectators at the arguments. Also in attendance was retired Justice Sandra Day O'Connor, who wrote the majority opinion in a 2003 case that upheld the use of race in college admissions.