WASHINGTON (Reuters) - A U.S. court on Thursday rejected a bid by Republican voters to throw out congressional districts drawn by Democratic lawmakers in Maryland.

The three-judge panel sitting in Baltimore, divided 2-1, also put any further action in the case on hold pending the U.S. Supreme Court’s upcoming decision in a similar case from Wisconsin that could set a new test for how courts nationwide handle such claims.

At the heart of the Maryland case was the decision to redraw the state’s sixth congressional district, previously held by a Republican and now held by a Democrat.

The challengers say the move was a partisan gerrymander in violation of the U.S. Constitution because it intentionally diluted the Republican vote. Gerrymandering is the manipulation of electoral boundaries to gain a political advantage.

After the new map was introduced, Republican Representative Roscoe Bartlett lost in the 2012 election to Democrat John Delaney. Democrats now hold seven of the state’s eight congressional seats. The state’s governor, Larry Hogan, is a Republican.

“The widespread nature of gerrymandering in modern politics is matched by the almost universal absence of those who will defend its negative effect on our democracy,” Judge Paul Niemeyer, a Republican appointee, wrote in his dissenting opinion.

“Indeed, both Democrats and Republicans have decried it when wielded by their opponents but nonetheless continue to gerrymander in their own self interest when given the opportunity,” he added.

The other two judges are Democratic appointees.

On Oct. 2, the U.S. Supreme Court will hear oral arguments over Republican line-drawing in Wisconsin, which Democrats say diluted their votes.

The case gives the court an opportunity to issue a ruling saying whether or not challenges to gerrymandering can be brought over maps drawn solely on partisan grounds. The court has previously thrown out maps when there is evidence the state had sought to dilute the vote of a racial minority.

The high court’s decision could dictate whether the Maryland case can move forward.