Adam Liptak is the Supreme Court correspondent for The New York Times.

Washington

ABIGAIL FISHER, a white student, says she was denied admission to the University of Texas because of her race. She sued in Federal District Court in Austin, causing Judge Sam Sparks to spend time trying to make sense of a 2003 Supreme Court decision allowing racial preferences in higher education. “I’ve read it till I’m blue in the face,” Judge Sparks said in an early hearing in Ms. Fisher’s lawsuit. But the meaning of the central concept in the decision — “this esoteric critical mass of diversity of students,” he called it — kept eluding him.

The 2003 Supreme Court decision he was trying to understand, Grutter v. Bollinger, had elevated the concept of “diversity” from human-resource department jargon to constitutional stature. The pursuit of diversity, a five-justice majority said, allows admissions personnel at public universities to do what the Constitution ordinarily forbids government officials to do — to sort people by race.

Judge Sparks in the end ruled that the Grutter decision meant that Texas was allowed to take account of Ms. Fisher’s race. Now her case is hurtling toward the Supreme Court. That could provide a fresh opportunity to consider what we mean when we talk about diversity. It could also mean the end of affirmative action at public universities.

Ms. Fisher’s lawyers filed a petition seeking a Supreme Court review last month, and legal experts say the justices will probably agree to hear it, setting the stage for a decision by June. Such a decision, given changes in the membership of the court since 2003, is likely to cut back on if not eliminate the use of race in admissions decisions at public colleges and universities.