“By meticulously targeting measures that were most used by people of color — in addition to imposing a restrictive photo ID requirement — the legislature sought to disturb the levers of power in North Carolina, ensuring only a select few could participate in the democratic process,” Penda D. Hair, co-director of the Advancement Project and a critic of the law, said in a statement. “This fight is not over.”

In his ruling, the judge suggested that past discrimination had abated. “There is significant, shameful past discrimination,” he wrote. “In North Carolina’s recent history, however, certainly for the last quarter century, there is little official discrimination to consider.”

The law, which originally included a much stricter voter ID provision, was passed by the Republican-controlled legislature in summer 2013, shortly after the Supreme Court’s 5-to-4 ruling in Shelby County v. Holder.

The ruling effectively eliminated what was known as the “preclearance” process, in which certain states and local governments had to submit proposed voting changes to the Justice Department or to a federal court in Washington.

Judge Schroeder’s decision capped a trial court record that stretched more than 23,000 pages and included weeks of testimony about the General Assembly’s revisions to the election laws here. The voter identification standard, which required voters to display one of six forms of documentation, was central to an overhaul that supporters described as a bulwark against fraud.

But opponents of the changes said they were intended to disenfranchise black and Hispanic voters, an assertion they repeated on Monday.

“Through widespread actions, rallies, marches and protests, we have said all along that we would accept no less than unabridged access to the ballot for all eligible voters,” said the Rev. William J. Barber II, the president of the North Carolina N.A.A.C.P. “Just like those who carried on before us, we will continue our movement challenging regressive and discriminatory voter suppression tactics on behalf of African-Americans, Latinos, seniors, students and all those for whom democracy has been denied.”