If the court overturns the provision, nine states, mainly in the South, would be free to change their voting procedures without getting permission from federal officials first.
The court’s conservatives suggested during oral arguments on Wednesday that the South has outgrown its past and the legal burdens on the nine states no longer are justified.
Crucial swing voter Justice Anthony Kennedy asked whether Alabama now is an “independent sovereign” or whether it must live “under the trusteeship of the United States government.”
Justice Antonin Scalia said the law amounts to a “perpetuation of racial entitlement.”
That remark generated what the New York Times says was the sharpest exchange of the morning, with Justice Sonia Sotomayor asking a lawyer challenging the law, "with an edge in her voice": “Do you think that racial discrimination in voting has ended, that there is none anywhere?”
The ruling is due by the end of June.