WASHINGTON - Abigail Noel Fisher lost her shot at attending the University of Texas as an undergraduate, but she appears to have a good chance at changing college admissions nationwide.

In a potentially landmark case, the Supreme Court on Wednesday will take up Fisher's challenge to race-based admissions policies. Because of personnel changes and the passage of time, the conservative-led court could readily scale back what kind of affirmative action can be permitted.

"I don't think anyone thinks affirmative action is long for this world," said Pamela Harris, a visiting professor at the Georgetown University Law Center.

The hour-long oral argument Wednesday morning will test whether giving minority applicants some competitive advantage violates the 14th Amendment's requirement that states grant "the equal protection of the laws" to all people. Schools have been struggling with this balance between diversity and equal protection, with different outcomes.

The University of Texas, for one, guarantees admission to students from the top 10 percent of their high school classes. For the rest, the school considers race along with other "special circumstances," such as socioeconomic status.

The Texas school says its admissions programs help the educational experience and comply with the Constitution.

"Diversity improves academic outcomes and better prepares students to become the next generation of leaders in an increasingly diverse society," attorney Gregory Garre wrote on behalf of the university.

He called race "only one modest factor among many others weighed."

The Supreme Court last addressed affirmative action in college admissions in 2003, with a 5-4 decision upholding the University of Michigan Law School's use of race as one factor among many.

Justice Sandra Day O'Connor wrote the majority opinion that identified the "educational benefits that flow from a diverse student body," even as she stressed that "we expect 25 years from now, the use of racial preferences will no longer be necessary."

The constitutional clock seemed to speed up with O'Connor's 2005 retirement and her replacement by Justice Samuel Alito. Alito is more skeptical about race in college admissions. Moreover, Justice Elena Kagan, who replaced affirmative action supporter John Paul Stevens in 2010, has recused herself because of her prior role as the Obama administration's solicitor general.

"It's quite likely the University of Texas program will be in big trouble," predicted attorney and prominent Supreme Court blogger Tom Goldstein.

Justices Antonin Scalia, Clarence Thomas and Anthony Kennedy all voted against the Michigan affirmative action plan in 2003. In addition to Alito, the court's post-2003 members include Chief Justice John Roberts Jr., who has, likewise, criticized race-based decision-making in other school settings.

Court watchers suggest Roberts may have further strengthened his hand against affirmative action by his role in June in upholding the Obama administration's health care law.

By this tactical reasoning, Harris of the Georgetown law center said that Roberts "built up some credibility and capital" as an independent thinker that he can now draw upon in another controversial case.