Rep. Bobby Scott (D-Va.), left, speaks to former secretary of education Richard Wilson Riley in the Longworth House Office Building during a music education event in Washington in May. (Kris Connor/Getty Images for NAMM)

A panel of federal judges issued a ruling Friday that Virginia lawmakers illegally concentrated African American voters into one congressional district to reduce their influence elsewhere, bringing the state a step closer to being forced to redraw its election map.

The U.S. District Court for the Eastern District of Virginia affirmed its earlier decision and ordered the Virginia House of Delegates to redraw the state’s 11-district congressional map by Sept. 1.

The costly and time-consuming process would force the General Assembly back to Richmond for a special session this summer.

But an appeal from the state’s congressional Republicans could derail that timetable.

Attorney Michael A. Carvin, who represented Virginia’s Republican congressional delegation in their appeal of the court’s decision, said another appeal is likely.

“There’s a good chance that we will,” he said. “It was wrong for the same reason the original decision was wrong.”

Democrats and advocates for reducing the influence of politics on redistricting applauded Friday’s decision. And they could benefit politically: Diluting the African American makeup of the state’s black-majority district would make adjacent districts less Republican and potentially vulnerable to Democratic challenge.

The suit was brought by Marc E. Elias of the law firm Perkins Coie and funded by the National Democratic Redistricting Trust.

“I’m happy that the federal court, for the second time, has found that the Republican legislative map was an unconstitutional racial gerrymander,” Elias said. “I look forward to the state of Virginia enacting a constitutional map by the September 1st deadline that the court provided.”

House of Delegates Speaker William J. Howell (R-Stafford) said he supports letting the case play out fully in court.

“The House of Delegates fully intends to exercise its legal right to attempt to remedy any flaw ultimately found by the courts with respect to the current congressional districts,” he said. “However, we maintain that the defendants should have the opportunity to fully litigate this case.”

Because of the special nature of redistricting challenges, appeals from three-judge panels go directly to the U.S. Supreme Court. The justices are required to summarily affirm or reverse the decision or accept the case for full briefing and argument.

The case could foreshadow the court’s decision in a separate but very similar case — also brought by Elias — that calls into question the constitutionality of a dozen Virginia House of Delegates districts on similar grounds. That case has yet to go to trial.

The stakes are high for Howell in the legislative case because his Republican supermajority helped craft and ultimately approved the maps. He also petitioned to be part of the case to defend them.

Republicans hold eight of the state’s 11 congressional seats — a lopsided reality that stands in contrast to the fact that the GOP has not won a statewide election in Virginia since 2009. Democrats regularly point to that statistic as evidence of the gerrymandering of district boundaries.

In October, the same federal court ruled similarly — that the General Assembly must redraw the congressional maps because the current plan “packs” African American voters into Democrat Robert C. Scott’s 3rd Congressional District at the expense of their influence elsewhere.

While an appeal from the congressional delegation played out in that case, the Supreme Court in March made a high-profile ruling in an Alabama case, requiring lower courts to look more closely at whether lawmakers make race the predominant factor in drawing new district lines after the 2010 census.

Around the same time, the high court ordered the lower court in the Virginia case to reconsider its decision to uphold district maps — which it did on Friday.

The Virginia and Alabama cases hinge on when it is legal to use race to draw district boundaries.

Del. Charniele L. Herring (D-Alexandria), chairwoman of the House Democratic Caucus, said she was not surprised by Friday’s ruling.

“We need to redraw the map. It’s important that the voters choose their representatives and not the other way around,” she said.

Redistricting is regularly blamed for the partisanship that often defines the legislative process.

In this year’s General Assembly session, proponents of nonpartisan redistricting pushed to remove politics from the process with a raft of bills but none passed.

Advocates of restructuring argue that under the current system, districts are drawn to protect incumbents. As a result, they tend to include populations that lean heavily toward one party over the other — attracting candidates who appeal to the extremes of their parties at the expense of bipartisanship and moderation.

Brian Cannon, executive director of OneVirginia2021, which pushes for nonpartisan redistricting, said: “This just proves the General Assembly can’t handle the responsibility of doing this without some kind of reform.”

Robert Barnes contributed to this report.