The Supreme Court's conservative majority appeared to look favorably on Michigan's voter-approved law that bans use of racial criteria in college admissions.
An hour of oral arguments Tuesday afternoon raised anew thorny, unresolved questions over race and remedies.
The justices are being asked to decide the constitutionality of a 2006 referendum that prohibits race- and sex-based discrimination or preferential treatment in public university admission decisions. That ban was written into the state's constitution.
The high court appeared to divide along ideological lines over whether the law has the effect of restructuring the political process to make it harder for minority groups to enact policies benefiting them, in possible violation of the 14th Amendment.
"It seems the goal posts keep changing every few years for minorities," said Justice Sonia Sotomayor, over efforts to blunt or eliminate affirmative action.