A federal judge on Friday granted New Jersey Democratic Rep. Andy Kim’s request for a new ballot design, dealing a blow to the Garden State’s political machine.

Kim, who is running for Senate this year, and two House candidates filed a lawsuit in February challenging the state’s unique ballot design known as the “county line.” In that design, candidates endorsed by a county party are grouped together in a single row or column, and other candidates competing for the same offices appear off the side.

Kim and his allies pushed for an “office-block” ballot, where candidates are instead grouped by office, arguing the county line system unfairly benefited candidates backed by party leaders.

U.S. District Judge Zahid N. Quraishi on Friday sided with the plaintiffs, ordering counties to use office-block style ballots for the upcoming June 4 primary.

“The integrity of the democratic process for a primary election is at stake and the remedy Plaintiffs are seeking is extraordinary,” Quraishi wrote in his 49-page ruling, adding that the plaintiffs faced a “particularly heavy” burden to prove their case.

“Nevertheless, the Court finds, based on this record, that Plaintiffs have met their burden and that this is the rare instance when mandatory relief is warranted,” Quraishi wrote. 

The county clerks named as defendants in the lawsuit could still fight the decision. A spokesperson for the defense counsel told the New Jersey Globe that lawyers are “evaluating their options to appeal.”

But if Quraishi’s decision stands, it would be a major blow to the Democratic Party machine in New Jersey, where county party chairs can wield significant power. In some of of the most Democratic counties, the party endorsement is decided by a single party chair. Kim and his allies argued that process is ultimately undemocratic.

“Today’s decision is a victory for a fairer, more democratic politics in New Jersey,” Kim said in a statement on Friday. “It’s a victory built from the incredible grassroots work of activists across our state who saw an undemocratic system marginalizing the voices of voters, and worked tirelessly to fix it.”

Kim’s lawsuit moved forward even after his chief rival in the Democratic Senate primary, first lady Tammy Murphy, ended her campaign on Sunday. While Kim had won some county lines where the party’s endorsement was decided at conventions, Murphy had the backing of several party chairs who were the sole arbiters of their counties’ endorsements.

Kim launched his Senate campaign in September after Democratic Sen. Bob Menendez was indicted on federal bribery charges. Menenedez, who has denied any wrongdoing, has said he could run for re-election as an independent if he is exonerated.