The two Republican candidates in the Sept. 9 primary for the at-large seat on the D.C. City Council, incumbent Jerry A. Moore Jr. and his principal challenger, Joe Grano, are sniping over which one of them might be a closet Democrat.

Grano has based his candidacy on the assertion that Moore, the Council's only Republican since he was appointed by Richard Nixon in 1969, has consistently voted with the Democratic majority. "If it walks like a duck and quacks like a duck, it's a -- duck -- and Jerry Moore is a Democrat," Grano said.

But Moore is pointing out that Grano was a registered Democrat in New York City for several years, and only switched to the Republican Party when he moved to the District in 1977.

Moore has sent that message out -- that he, not Grano, is the true Republican -- in a blanket mailing this week to the District's registered Republicans, according to Moore's campaign office manager, Alice Banks.

Grano shrugs away the challenge to his Republican credentials, saying that "they've twisted it." He said, "The issue is not whether or not I was ever a Democrat, the issue is Moore's voting record as a public official."

Grano, 35, said he registered as a Democrat in New York City at 21 years of age, "when I didn't know any better," and despite the fact that he came from a longtime conservative Republican family.

"When I was 21 years old, someone told me if you want to get anywhere in this town (New York), you have to be a Democrat," Grano said. He said he'd never actively participated in the Democratic Party, and in primary elections, I always picked the most conservative Democrat I could find."

Grano said he always voted for Republican candidates in presidential elections.

Grano said he became more conservative as a teacher in the South Bronx, when liberal newspaper editorials often blamed the teachers for the poor quality of public education. Grano came to Washington in 1977, as an attorney for the Board of Veterans Appeals, and "literally one of the first things I did was register as a Republican; I wanted to wipe the slate clean."

Grano has been trying to make Moore's voting record the key issue in the campaign, by casting himself on his brochures and campaign literature as "A Republican for a Change."