Top US court considers case on racial redistricting

The US Supreme Court on Monday took up a lower court's ruling that some Virginia districts were deliberately redrawn to diminish the impact of the African American vote -- an urgent issue as the eastern swing state prepares for legislative elections.

The state, whose population is nearly 20-percent black, underwent redistricting in 2011 by the House of Delegates, the lower house of the state legislature.

Residents mounted a legal challenge, arguing that the electoral map was drawn to concentrate African American voters in certain districts, in order to diminish their influence in other districts.

The stakes are important in a country where most blacks vote for Democrats, while whites tend to favour Republicans.

A lower court found in favour of the plaintiffs but the Supreme Court, the first time it took up the issue, found that the court's arguments were flawed and sent the case back.

In its new ruling, the lower court found that voters' skin colour had played a preponderant role in the mapping of 11 districts, in violation of the US Constitution.

The court's judges approved a redistricting map drawn up to correct the 2011 map, and analysts say the changes appear to favour Democrats.

The House of Delegates' majority Republicans are appealing the lower court ruling to the Supreme Court.

The nation's top court must first decide whether the Republican members of the lower house have standing to appeal the ruling. Normally, it would fall to the state's attorney general to appeal but Virginia's attorney general, a Democrat, has opted not to do so.

At Monday's hearing, Justice Sonia Sotomayor of the high court's liberal wing warned accepting the Republicans' standing to appeal "would invite complete discord in the state."