WASHINGTON — In a major blow to civil rights activists, the Supreme Court on Tuesday struck down an important part of a 48-year-old federal law designed to protect minority voters.
The court ruled on a 5-4 vote in favor of officials from Shelby County, Alabama, in finding that a section of the landmark 1965 Voting Rights Act that sets the formula that determines which states need federal approval to change voting laws is invalid.
Writing for the majority, conservative Chief Justice John Roberts said the coverage formula that Congress used when it most recently reauthorized the law in 2006 should have been updated.
"Congress did not use the record it compiled to shape a coverage formula grounded in current conditions," he wrote. "It instead re-enacted a formula based on 40-year-old facts having no logical relationship to the present day."
The court, split on ideological lines, did not go as far as striking down Section 5 of the law, known as the preclearance provision, which requires certain states to get approval from the Justice Department or a federal court before making election-law changes.
But a majority did invalidate Section 4 of the act, which sets the formula for states covered by Section 5 and was based on historic patterns of discrimination against minority voters.
Although Section 5 is technically left intact, it is effectively nullified, at least for the near future, as Congress would now need to pass new legislation setting a new formula before it can be applied again.
As a result, the ruling is a heavy blow for civil rights advocates, who believe the loss of a working preclearance program could lead to an increase in attempts to deter minorities from voting. They say that 31 proposals made by covered jurisdictions to modify election laws have been blocked by the Justice Department under Section 5 since the law was re-enacted in 2006.
One of the most closely watched disputes of the court's current term, the case centers on the civil rights-era law that broadly prohibited poll taxes, literacy tests and other measures that prevented blacks from voting. In the 1960s, such laws existed throughout the country but were more prevalent in the South with its legacy of slavery.
Section 5 of the law required certain states, mainly in the South, to show that any proposed election-law change does not discriminate against black, Latino or other minority voters.
The nine fully covered states were Alabama, Alaska, Arizona, Georgia, Louisiana, Mississippi, South Carolina, Texas and Virginia.
The Shelby County challengers said the kind of systematic obstruction that once warranted treating the South differently is over and the screening provision should be struck down.
The Obama administration, backed by civil rights advocates, had argued that the provision was still needed to deter voter discrimination.
The issue of voting rights remains prominent in the United States. During the 2012 presidential election campaign, judges nationwide heard challenges to new voter identification laws and redrawn voting districts. The most restrictive moves ended up being blocked before the November elections.
Just last week, the Supreme Court struck down an Arizona state law that required people registering to vote in federal elections to show proof of citizenship, a victory for activists who said it discouraged Native Americans and Latinos from voting.
Democrats say that and similar measures, championed by Republicans at the state level, were intended to make it more difficult for certain voters who tend to vote Democratic to cast ballots.
The case is Shelby County v. Holder, U.S. Supreme Court, No. 12-96.