(ABC News) — The Pennsylvania Supreme Court Monday ordered that the state’s congressional map be redrawn in a move that could have major implications for the Democratic Party’s ability to re-take the U.S. House of Representatives in the 2018 midterm elections.

In the order from the court, which ruled 4-3, the judges found that the “Congressional Redistricting Act of 2011 clearly, plainly and palpably violates the Constitution of the Commonwealth of Pennsylvania” and mandated a new plan be submitted to the governor no later than February 9th.

According to the order, congressional districts in the state must be “composed of compact and contiguous territory; as nearly equal in population as practicable; and which do not divide any county, city, incorporated town, borough, township, or ward, except where necessary to ensure equality of population.”

The court decision is a victory for anti-gerrymandering activists – who argued that Pennsylvania’s congressional map gave an unfair partisan advantage to the state’s Republican Party.

The suit, originally brought by the League of Women Voters, contended that “in 2011 Pennsylvania elected officials manipulated the congressional district boundaries to entrench a Republican delegation in Congress and minimize the ability of Democrats voters to elect U.S. House representatives.”

Republicans were in control of the redistricting process in 2010, and have held a majority of the state’s congressional districts since the new map was put in place in 2011.

Pennsylvania was a key Rust Belt state that helped Donald Trump capture the White House in the 2016 presidential election. Trump won the state by just under 50,000 votes over Hillary Clinton.

The new map will need to be drafted by the Pennsylvania General Assembly and submitted to Governor Tom Wolf, a Democrat up for re-election in 2018.

Republicans currently control both houses of the general assembly, setting up another potential battle over a map that currently has the GOP in control of 12 of the state’s 18 congressional districts.

Reacting to the news, Governor Wolf said his office is reviewing the order and assessing their next steps.

“I strongly believe that gerrymandering is wrong and consistently have stated that the current maps are unfair to Pennsylvanians,” he said in a statement. “My administration is reviewing the order and we are assessing the executive branch’s next steps in this process.”

Unaffected by the order is the March 13th special election in Pennsylvania’s 18th congressional district between Republican State Sen. Rick Saccone and Democrat Conor Lamb. The court said in its order that that race will proceed under the old congressional map.

The decision by the Pennsylvania court comes just a week after the U.S. Supreme Court delayed a lower court order in North Carolina that would have forced that state to redraw its congressional district as well.

Democratic National Committee Chair Tom Perez celebrated the court’s decision as a “victory for democracy and another blow to the Republican Party’s nationwide effort to game the system.”

“Democrats believe that voters should pick their representatives, not the other way around. And we will keep fighting to make sure our election process is fair to every voter,” Perez wrote in a statement released Monday.

Democrats in the state, who are defending both the governor’s mansion and a U.S. Senate seat, in addition to six U.S. House seats, also hailed the court’s decision.

“The order issued by the Supreme Court today found that the congressional map violates Pennsylvania’s constitution and has provided the methodology for new maps to be submitted and acted upon before the end of February,” Pennsylvania Democratic Party Chairman Marcel Groen said in a statement. “I want to thank and compliment the attorneys and parties who brought this before the Supreme Court and helped right this obvious wrong.”

The chairman of the Pennsylvania GOP, Val DiGiorgio, vowed to fight the court ruling.

“The Pennsylvania Supreme Court’s politically motivated decision is a partisan attempt to overturn the will of the legislature, which approved these congressional maps with Democrat votes in 2011. Back in 2010, this same court said these district lines were constitutional – the only things that have changed between then and now are makeup of the court and Democrats being dissatisfied with the results,” he said in a statement.

DiGiorgio called it a decision by “judicial activists,” adding, “By legislating from the bench, Pennsylvania’s Supreme Court is throwing our elections into chaos and confusion. We intend to support efforts to secure a stay from the United States Supreme Court, similar to the recent stay granted in North Carolina.”