WASHINGTON (AP) — A federal judge on Wednesday questioned whether a key component of the landmark Voting Rights Act is outdated, expressing skepticism about using evidence of racial discrimination from 40 or 50 years ago to justify continued election monitoring for a group of mostly Southern states.

U.S. District Judge John Bates’ comments came during oral arguments in an Alabama county’s lawsuit targeting the law — a constitutional challenge that a number of legal observers predict could well reach the Supreme Court.

Shelby County, backed by conservative legal groups, maintains that it and other covered state, county and local governments should no longer be forced to get federal approval before changing even minor election procedures. They note that the Voting Rights Act — enacted in 1965 and extended by Congress for another 25 years in 2006 — relies heavily on past discrimination in determining which jurisdictions are covered by the “pre-clearance” requirement for election changes such as moving a polling place or redrawing school district lines.

Bates at times appeared sympathetic to the county’s argument but also posed some sharp questions to its legal team.

“We’re now looking at a situation where that information is at least 45 years out of date, and by the time the 2006 extension of the Voting Rights Act runs its course it will be 70 years,” he said. “That wouldn’t seem to be a current coverage formula, would it?”

Justice Department attorneys, supported by lawyers for several civil rights groups, responded that Congress extended the law with overwhelming majorities based on evidence that racial discrimination continues today. The new forms of discrimination — while more subtle — are most common in the jurisdictions with the most checkered racial pasts, they argued.

“The question is: Is there continued discrimination in those covered states? And the answer is yes,” said Samuel Bagenstos, the Justice Department’s lead attorney in the case.

Civil rights groups have pointed to a variety of examples in which local governments have redrawn district lines or delayed elections in an effort to dilute minority voting strength.

The NAACP Legal Defense Fund, for example, points to a recent case in Calera, Ala., a fast-growing city in Shelby County, south of Birmingham. The city eliminated its only black-majority city council district when it redrew the district lines in 2006. After the change, Calera’s only African-American councilman, Ernest Montgomery, lost his seat. But citing the Voting Rights Act, the Justice Department under President George W. Bush voided the election and required Calera to redraw the boundaries, restoring the black-majority district. Montgomery was re-elected.

On Wednesday, Shelby County’s attorneys argued that such redistricting is taking place across the country, as much in New Jersey or Illinois as in the jurisdictions covered under the Voting Rights Act. The law’s formula, said attorney William Consovoy, “is archaic … it doesn’t bear at all on the current conditions in the country.”

Bates reserved decision. He said he had a lot of work to do on the case. Attorneys involved predicted it might take him several months to rule.

Copyright 2011 The Associated Press.