By Ariane de Vogue, Ryan Nobles and Devan Cole, CNN

(CNN) -- In a victory for Democrats in Virginia, the Supreme Court held Monday that the Republican-led Virginia House of Delegates did not have the legal right to challenge a lower court opinion that struck several district maps they had drawn as an unconstitutional racial gerrymander.

This means court-ordered maps that favored Democrats will continue to be used.

The decision will have an immediate impact on Virginia's fall legislative elections at a crucial time. The state, once reliably Republican, has slowly drifted left. Republicans have not won a statewide race since 2009, but they have held on to both the Senate and House by slim margins. This fall, every state legislative seat is up for re-election and the GOP holds only a two-seat advantage in both chambers.

Had the court ruled in favor of the Republican challenge, it would've greatly improved their chances of holding on to the House of Delegates. Twenty-six House districts were re-aligned by an outside expert after a lower court ruled 11 districts unconstitutional.

Justice Ruth Bader Ginsburg wrote the opinion for a 5-4 court, joined by Justices Clarence Thomas, Sonia Sotomayor, Elena Kagan and Neil Gorsuch.

Because the Supreme Court dismissed the challenge on standing grounds, justices did not rule if the maps constitute an unconstitutional racial gerrymander.

"One House of its bicameral legislature cannot alone continue the litigation against the will of its partners in the legislative process," Ginsburg wrote.

"If the State had designated the House to represent its interests, and if the House had in fact carried out that mission, we would agree that the House could stand in for the State. Neither precondition, however, is met here."

In a statement released on Monday, the Speaker of the House of Delegates Kirk Cox, who brought the suit, vowed that the redistricting battle is not over.

"Unfortunately, the Court's decision to not decide the merits of this case leaves a number of unanswered questions just two years before the next redistricting cycle," said Cox. "This could have been prevented if Attorney General (Mark) Herring would have defended the law of the Commonwealth and allowed the court to provide an opinion on the merits of this case."

Herring declined to defend the re-drawn districts when they were challenged in court. In a tweet posted Monday, Herring lauded the decision by the high court.

"The US Supreme Court has rejected Virginia Republicans' efforts to protect racially gerrymandered districts. Virginia's elections this fall will take place in fair, constitutional districts. It's a good day for democracy in Virginia," Herring wrote.

Former US Attorney General Eric Holder, who chairs the National Democratic Redistricting Committee, an organization whose goal is to end Republican gerrymandering, said in a statement on Monday that the Court's decision "is an important victory for African Americans in Virginia who have been forced since 2011 to vote in racially gerrymandered districts that unfairly diluted their voting power."

"With a new, fair map in place, all Virginians will now -- finally -- have the opportunity this fall to elect a House of Delegates that actually represents the will of the people," Holder said.

Beyond the immediate impact of this fall's elections, the decision could have a far reaching implication on Virginia politics. If Democrats flip either or both chambers this fall, they will be well positioned to control the next round of redistricting after the 2020 census.