A U.S. Supreme Court decision reviving a challenge to several Virginia legislative districts could send lawmakers back to the drawing board, but Republicans say they are confident the state's current electoral map will withstand further scrutiny.

The justices on Wednesday tossed out a ruling that upheld 11 districts in which African-Americans made up at least 55 percent of eligible voters and ordered the lower court to re-examine the boundaries. The lawsuit accused lawmakers of illegally packing black voters into certain districts to make surrounding districts whiter and more Republican.

Democrats say they're certain the lower court will find the districts unconstitutional and force lawmakers to redraw them. Marc Elias, an attorney for the Virginia voters who brought the case, said they will push for that to happen before the November elections.

"It's important that the people of the Commonwealth don't have to have another election using unconstitutional district lines, and we will move forward as quickly as possible to make sure we have constitutional and fair lines in place for the 2017 elections," Elias said.

The top Republican in the Virginia House, however, said he's confident that the current boundaries will stand.