Black political leaders in Northern Virginia yesterday expressed mixed opinions about whether a Virginia NAACP campaign for ward instead of at-large elections would help elect more blacks to local government in Alexandria.

"We looked at some of the reasons why you don't find blacks serving in public office in cities that have a large black population . . . and we just said this is a natural thing for us to do," said Michael Brown, the state NAACP coordinator in Richmond for branch and field activities. The Virginia NAACP has targeted Alexandria and 10 other cities in its campaign.

Brown said Alexandria, which has a 22.3 percent black population and one black on its seven member City Council, was selected solely on its ratio of black population to elected officials. Civil rights leaders traditionally have viewed the ward system, in which elected officials are chosen from specific districts, as a way to insure that blacks will win their fair share of seats in local government.

But in Alexandria, Ulysses Calhoun, the president of the Alexandria chapter of the NAACP, gave the plan for promoting ward elections a weak endorsement, saying that it "might help here."

Because of what Calhoun said is a widespread migration of whites into formerly black areas just west of Old Town, there are few remaining black communities large enough to elect blacks if ward elections--held in the city from 1932 to 1948--returned to Alexandria.

"I really don't know why Alexandria was picked," he said. "The black population is so scattered because housing opportunities are pretty open."

Lionel Hope, the only black member of the Alexandria City Council, agreed.

"My feeling is that in a city like Alexandria a ward system wouldn't be practical," he said. "There are some neighborhoods that are solidly black, but not to the proportion that would make me feel that we would need to go to the ward system."

Hope added that he favored at-large elections because it encourages elected officials to represent all of the city. Hope said ward elections would give black elected officials a limited mandate.

"It would render them not as effective," he said.

George Lambert, director of the Northern Virginia Urban League, said, however, he believed that the black vote would be enhanced by switching to a ward system.

"You still have identifiable concentrations of blacks that would, perhaps, have a better chance of getting someone elected that is black," Lambert said.

Black leaders often point to four predominantly black precincts in Alexandria, most of which are located just west of Washington Street, as strongholds of black voting power. This month's figures on registered voters in those precincts--Cora Kelly School, Fire House Four, Jefferson Houston School and Lee Center--show a total of 3,846 registered voters out of the city's 46,009 registered voters.

"Changing to a ward system could enhance our chances," said Melvin Miller, longtime black activist in Alexandria politics. "But the change wouldn't guarantee it."

Brown said the NAACP will soon begin meetings with the black leadership from the targeted communities. And if the NAACP feels that blacks have had healthy participation under the at-large system, it will not advocate a change to the ward system.

He said the NAACP plans to expand the scope of its campaign to include other Virginia locations. Alexandria is the only city in the Northern Virginia area named by the NAACP so far.