Francis X. De Luca, president of the Civitas Institute, a conservative North Carolina think tank, said it was about time that the federal government returned decision making to the local level. Forty of North Carolina’s 100 counties had been required to submit election changes for preclearance.

“This is something that local people can work out,” Mr. De Luca said.

Voting rights advocates are less trusting, as are, generally, Democrats, whose success in states like North Carolina is dependent on ensuring high black voter turnout.

Advocates say it is difficult to monitor, let alone quantify, all of the local election law changes in the areas freed from government review, since the Justice Department is no longer notified of the changes they make.

But a number of cases around the South have made news. In Pasadena, Tex., voters in November narrowly approved a City Council redistricting plan that critics said diluted the political power of Latinos.

Earlier this year, the American Civil Liberties Union filed suit in Augusta, Ga., over a plan that moved mayoral and City Council elections from November to May, concerned that black voters would be less likely to go to the polls at the later date. The suit was dismissed by a federal judge in May.

Bob Hall, executive director of Democracy North Carolina, a liberal group, rattled off a number of small-scale recent cases that he said had harmed black voters in his state: the moving of an early voting site in Hoke County; the relocation of some polling places in Rockingham County; and changes to school board districts in Guilford County.