A Maryland judge tossed the state’s congressional map, calling it an “extreme partisan gerrymander” in a ruling Friday that gave the state just a few days to arrive at a new plan.

Judge Lynne A. Battaglia, who found the map violated the Maryland constitution’s protections for fair elections, gave the legislature until March 30 to draw a new map. The state has an April 15 filing deadline in advance of a July 19 primary.

The ruling noted the decision could be appealed to a state court of appeals.

Fair Maps Maryland, an advocacy group associated with case plaintiffs, including Republican state lawmakers, praised the ruling in a statement.

“To call this a big deal would be the understatement of the century. Judge Battaglia’s ruling confirms what we have all known for years — Maryland is ground zero for gerrymandering, our districts and political reality reek of it, and there is abundant proof that it is occurring,” the organization said.

A representative for Maryland Attorney General Brian Frosh said in a statement the office was still reviewing the decision and had not made a decision about an appeal.

While the Maryland Gov. Larry Hogan is Republican, the state’s legislature and the attorney general’s office are controlled by Democrats.

Maryland has an advisory redistricting commission, but the legislature has the final power to draw maps in the state. Democrats in the legislature overrode Hogan’s veto to put the map in place last year. The eight-member map is currently represented by only one Republican, Rep. Andy Harris.

Redistricting advocacy group RepresentUs also praised the decision in a statement from CEO Joshua Graham Lynn, who called Maryland’s map “a textbook example of extreme partisan gerrymandering.”

According to the Princeton Gerrymandering Project, which has evaluated congressional maps throughout the country, the Maryland map gave Democrats an advantage over Republicans in all eight of the state’s congressional districts.

In an analysis by the group, Harris represented the least Democratic seat in the state, which had a 2 percentage point Democratic lean.

The ruling is the first such state court case against a map that favors Democrats. In earlier cases in Ohio and North Carolina, state judges have rejected district lines that favor Republicans.

The Supreme Court ruled in Rucho v. Common Cause in 2019 that federal courts could not consider partisan gerrymandering claims because they were best left to the states.

The Ohio Supreme Court has rejected several efforts by its legislature to draw a congressional map, finding each time that the legislature violated a state constitutional protection against overly partisan districts.

In North Carolina, the state Supreme Court issued a 4-3 ruling requiring the state to draw a new map with a partisan breakdown more closely resembling the state’s overall voting results.

Then last month, a three-judge panel in North Carolina selected a map drawn, by a court-designated expert, that had a partisan breakdown closer to the state’s overall presidential results. The map will only stay in place through the 2022 midterm elections due to state law.

Republicans in North Carolina appealed the state court’s ruling to the Supreme Court on an emergency basis but were denied. In a concurring opinion to that decision, Justice Brett M. Kavanaugh wrote the court could take up the issue of state court gerrymandering decisions in the future.