In a decision that could have significant repercussions for the balance of power in the closely divided U.S. House, North Carolina’s highest court on Friday reversed an earlier ruling that declared partisan gerrymandering illegal.

The 5-2 decision by the Republican majority on the court will allow the Republican-controlled legislature to redraw district boundaries for both Congress and the General Assembly to favor GOP candidates. Both Democratic justices were in the minority.

North Carolina’s congressional delegation is currently evenly divided, with seven Republicans and seven Democrats. But the court’s decision empowers Republicans in Raleigh to remake the map, which could place at least three of those Democrats in jeopardy.

“Here in North Carolina, the voters have become very party loyalists and have pretty much sorted themselves geographically, so I think the expectation is that we will go from what is now a 7-7 congressional delegation to likely 11-3 — or maybe pushing 12-2,” said Michael Bitzer, chairman of the politics and history department at Catawba College in Salisbury, N.C.

“With this carte blanche that Republicans in the legislature have now, anything and everything to maximize their seats in the congressional delegation and in the state legislative chambers is on the table,” Bitzer added.

The court on Friday also overturned another recent case related to voting, reversing a decision that found a law requiring voters to present a photo ID was racially biased and violated the equal protection clause of the state Constitution. That ruling also came in a 5-2 vote along party lines.

The North Carolina Republican Party hailed both rulings, saying they mark the return of “common sense election integrity protection” following “years of partisan subversion” by Democratic judges.

“The people of North Carolina rejected the blatant activism of the progressive judges by electing a strong majority of conservative justices,” Michael Whatley, chairman of the North Carolina GOP, said in a statement. “These rulings are a big step toward restoring respect for the Constitution and taking politics out of the courtroom.”

Rep. Suzan DelBene, chairwoman of the Democratic Congressional Campaign Committee, blasted the court’s decision. “Today’s ruling by an extreme Republican majority on the North Carolina Supreme Court is both unprecedented and an outrageous affront to voters who deserve fair, non-gerrymandered maps,” DelBene, D-Wash., said in a statement. “This is nothing more than a partisan power grab and a slap in the face to North Carolinians.”

Among the Tar Heel State Democrats now considered vulnerable are freshmen Reps. Wiley Nickel and Jeff Jackson as well as Rep. Kathy Manning, currently serving her second term, Bitzer said. Freshman Rep. Don Davis, who represents a slice of northeastern North Carolina along the Virginia border, is also potentially at risk.

Jackson denounced the decision on Twitter. “This is a huge loss for voters,” he said. “No matter how you vote, it diminishes your power.”

The ruling was widely expected after Republicans gained the majority of seats after November’s elections. The court took the unusual step of revisiting the decision, which had been handed down in December when Democrats held the majority.