(CBS News) WASHINGTON -- The Voting Rights Act has been the law of the land for nearly half a century, helping to ensure that minorities are not denied the right to vote. On Wednesday, Shelby County, Ala., challenged the law at the Supreme Court.
The arguments sharply divided the justices: The court's conservative majority appeared poised to strike down at least part of the act and eliminate the current federal oversight of voting in the South.
At issue is a decades-old provision in the law that requires nine states, mostly in the South, to get approval from the federal government before changing voting laws or procedures.
Justice Antonin Scalia called it a "racial entitlement."
Chief Justice John Roberts asked if the government believed "the citizens in the South are more racist than citizens in the North." Roberts said current data on voter turnout revealed more problems in Massachusetts than in Mississippi.
Congress did not rely on current data when, in 2006, it reauthorized the Voting Rights Act. It continued to rely on rates of minority voter registration and turnout in the elections of 1964, 1968 and 1972.
Alabama attorney Frank Ellis said Congress should look at the modern-day South.
"We ask for some recognition that we and these other converted jurisdictions have made great strides over the last 48 years," Ellis said.
The liberal justices strongly defended the law, saying Congress had thousands of pages of evidence documenting discrimination.
"Discrimination is discrimination, and what Congress said is it continues," Justice Sonia Sotomayor said.
Justice Stephen Breyer said, "The disease is still there ... it's gotten a lot better, a lot better, but it's still there."
That's why civil rights attorney Debo Adegbile said the provision is as necessary today as a generation ago.
"The problems are much more serious, much more repetitive, there is a much greater continuity in certain places than others," Adegbile said.
The liberal justices -- and the Obama administration -- say the court should defer to Congress, which they say is was better situated to make judgments about discrimination in voting. But based on the arguments today, it does appear a majority of the conservative judges are ready to tell Congress it's going to have to make some changes in that law.