"That does not mean state legislatures or courts cannot prevent the use of race, or that federal legislatures cannot prohibit the use of race," he said. "There are all sorts of ways that the people who overwhelmingly oppose the use of race can express their views."
But affirmative action proponents said they thought their movement had been reborn by the decision.
Marisa Demeo, a spokeswoman for the Mexican American Legal Defense and Education Fund, said California and Texas, having discontinued affirmative action at public universities, "must reexamine and reform their policies and practices in light of this new Supreme Court guidance."
A 1996 ruling by a federal appeals court that held the affirmative action plan at the University of Texas law school to be illegal is now "toast," asserted Wade Henderson, executive director for the Leadership Conference on Civil Rights.
That ruling had given rise to a statewide university admissions policy that the Bush administration had touted as an ideal alternative to affirmative action.
The plan guarantees admission to a percentage of all the top students at state high schools regardless of race. But some groups said they now expect an effort to overhaul the system and revive a form of affirmative action there.
"I think this is a victory for higher education. I also think that the court gave a road map of how we can get to creating diversity," said Martin Luther King III, president of the Atlanta-based Southern Christian Leadership Conference.
"We have not achieved true diversity in society as of yet, and we do not have a level playing field," he said. "If and when there is a level playing field ... we will not have the need for such programs as affirmative action."