WASHINGTON >> The Supreme Court said today it will consider eliminating the government’s chief weapon against racial discrimination at polling places since the 1960s.

Acting three days after the election, the justices agreed to hear a constitutional challenge to the part of the landmark Voting Rights Act that requires all or parts of 16 states with a history of discrimination in voting to get federal approval before making any changes in the way they hold elections.

The appeal from Shelby County, Ala., near Birmingham, says state and local governments covered by the law have made significant progress and no longer should be forced to live under oversight from Washington.

The high court considered the same issue three years ago but sidestepped what Chief Justice John Roberts then called “a difficult constitutional question.”

Since then, Congress has not addressed potential problems identified by the court. Meanwhile, the law’s opponents sensed its vulnerability and filed several new lawsuits.

Addressing those challenges, lower courts have concluded that a history of discrimination and more recent efforts to harm minority voters justify continuing federal oversight.

The justices said they will examine whether the formula under which states are covered is outdated because it relies on data that is now 40 years old. By some measures, states covered by the law are outperforming some that were not.

Tuesday’s election results also provide an interesting backdrop for the court’s action. Americans re-elected Barack Obama, the nation’s first African-American president. Exit polls across the country indicated Obama won more than 70 percent of Hispanics and more than 90 percent of blacks. In Alabama, however, exit polls showed Obama won only about 15 percent of the state’s white voters. In neighboring Mississippi, the numbers were even smaller, at 10 percent, exit polling found.

The case probably will be argued in February or March, with a decision expected by late June.

The advance approval, or preclearance requirement, was adopted in the Voting Rights Act in 1965 to give federal officials a potent tool to defeat persistent efforts to keep blacks from voting.

The provision was a huge success, and Congress periodically has renewed it over the years. The most recent occasion was in 2006, when a Republican-led Congress overwhelmingly approved and President George W. Bush signed a 25-year extension.

The requirement currently applies to the states of Alabama, Alaska, Arizona, Georgia, Louisiana, Mississippi, South Carolina, Texas and Virginia. It also covers certain counties in California, Florida, New York, North Carolina and South Dakota, and some local jurisdictions in Michigan and New Hampshire. Coverage has been triggered by past discrimination not only against blacks, but also against American Indians, Asian-Americans, Alaskan Natives and Hispanics.

Before these locations can change their voting rules, they must get approval either from the U.S. Justice Department’s civil rights division or from the federal district court in Washington that the new rules won’t discriminate.

Congress compiled a 15,000-page record and documented hundreds of instances of apparent voting discrimination in the states covered by the law dating to 1982, the last time it had been extended.

Six of the affected states, Alabama, Arizona, Georgia, South Carolina, South Dakota and Texas, are backing Shelby county’s appeal.

In 2009, Roberts indicated the court was troubled about the ongoing need for a law in the face of dramatically improved conditions, including increased minority voter registration and turnout rates. Roberts attributed part of the change to the law itself. “Past success alone, however, is not adequate justification to retain the preclearance requirements,” he said.

Jurisdictions required to obtain preclearance were chosen based on whether they had a test restricting the opportunity to register or vote and whether they had a voter registration or turnout rate below 50 percent.

A divided panel of federal appeals court judges in Washington said that the age of the information being used is less important than whether it helps identify jurisdictions with the worst discrimination problems.