The most obscure part of the federal Voting Rights Act is Section 3, which says that if a jurisdiction persistently demonstrates a disregard of voting rights for ethnic and racial minorities, it is subject to pre-clearance from the U.S. Justice Department. This section applies to the entire nation, but has almost never been used, because between 1965 and 2013, such jurisdictions were virtually always also required to obtain pre-clearance under Section 5.
On January 13, 2014, a U.S. District Court in Alabama used Section 3 to require the city of Evergreen to obtain approval from the Justice Department, if it makes changes to the voting rolls and also if it makes redistricting changes in its city council elections. The city had been placed under Section 5 in 2012. But in 2013, the U.S. Supreme Court made enforcement of Section 5 impossible, because the Court invalidated Section 4, which is linked to Section 5 and contains the formula to determine which parts of the nation are under Section 5.
The decision is Allen v City of Evergreen, southern district, 13-0107. Here is a newspaper story about the case.