By The Associated Press

A federal appeals court on Friday upheld a key provision of the Voting Rights Act, rejecting an Alabama county's challenge to the landmark civil rights law.

The provision requires state, county and local governments with a history of discrimination to obtain advance approval from the Justice Department, or from a federal court in Washington, for any changes to election procedures. It now applies to all or parts of 16 states, including Arizona.

In a 2-1 decision, the U.S. Court of Appeals for the District of Columbia Circuit said that Congress developed extensive evidence of continuing racial discrimination just six years ago and reached a reasonable conclusion when it reauthorized section 5 of the law at that time.

Judge David Tatel wrote for the majority that the court owes deference to Congress' judgment on the matter.

"Congress documented hundreds of instances in which the attorney general, acting pursuant to section 5, objected to proposed voting changes that he found would have a discriminatory purpose or effect," Tatel wrote.

Tatel said that in reauthorizing the law in 2006, Congress found serious and widespread intentional discrimination. The attorney general blocked discriminatory voting changes on 626 occasions, while state and local units of government withdrew over 800 proposed voting changes in response to Justice Department inquiries, Tatel said in summarizing the evidence Congress compiled.

In dissent, Judge Stephen Williams said the Voting Rights Act "imposes rather extraordinary burdens" based on information about discrimination that is several decades old.

Jurisdictions covered by Section 5 of the law were chosen based on whether they had a test restricting the opportunity to register or vote or whether they had a voter registration or turnout rate below 50 percent.

"It goes without saying that racism persists," wrote Williams. "But without more evidence distinguishing current conditions in the covered jurisdictions from those in the uncovered ones," the law's "coverage formula appears to be as obsolete in practice as one would expect" for evidence that is several decades old.

Addressing Williams's point, Tatel said the question is not whether old data is being used, but whether it helps identify the jurisdictions with the worst discrimination problems.

"If it does, then even though the formula rests on decades-old factors, the statute is rational," said Tatel.

Section 5 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, as well as some local jurisdictions in Michigan and New Hampshire.