A panel of federal judges on Tuesday handed down a decision against racial gerrymandering in Virginia, ruling that 11 legislative districts drawn by the Republican-controlled House of Delegates during the 2011 redistricting process are unconstitutional and discriminate against African-American voters.

Why it matters: The plaintiffs have argued that African-Americans, who overwhelmingly vote Democratic, were packed into certain districts to dilute their political influence and make surrounding ones more winnable for Republican candidates. In its 2-1 ruling, the court gave lawmakers until Oct. 30 to redraw the district lines.

The backdrop: Republicans argue that they used the 55% African-American voter threshold in order to comply with the Voting Rights Act.

• The VRA was meant in part to allow minorities to elect candidates of their choice. However, in recent years Democrats have argued that Republicans are using the act to justify packing too many minorities in districts.
• Meanwhile, as the Washington Post points out, this argument sometimes creates tension between minority groups and some black incumbent Democrats, who want to ensure that their “majority-minority” districts are safe for reelection. But other Democrats, and liberal advocates, want to disperse minority voters to increase the party’s ability to win more elections.

What they're saying: Former Attorney General Eric Holder, who's leading a national group to undercut Republicans’ sweeping control of the redistricting process in key states, said African-American voters have long "had their voting power diluted and their voices diminished. That will now change."

• Marc Elias, a Democratic lawyer representing the voters challenging the districts, lauded called the ruling a "big win for voting rights” in the state.

House Speaker Kirk Cox (R) plans to file "a prompt appeal" to the Supreme Court.

Republicans hold a 51-49 majority in the House of Delegates, a drop from 66-34 after a hotly contested election last November.