The city's preeminent gay political club last night endorsed the mayoral candidacy of D.C. Council member Charlene Drew Jarvis (Ward 4), in what could be a boost to Jarvis's efforts to lift herself above the pack of Democratic mayoral contenders.

Jarvis decisively defeated her closest competitor for the endorsement, Council Chairman David A. Clarke (D), by taking 49, or 63.6 percent, of the 77 votes cast last night by members of the Gertrude Stein Democratic Club.

Clarke won 19.5 percent of the vote, trailed by council member John Ray (D-At Large) and Sharon Pratt Dixon with 6.5 percent. Del. Walter E. Fauntroy (D-D.C.) and Calvin Gurley received no votes.

Jarvis said she believed the endorsement would prove as critical for her as it did for Marion Barry in 1978, when the gay community and members of the Stein Club provided what many say was the margin of victory in Barry's upset win in the Democratic primary.

"In 1978, this was the organization that identified the candidate that won," Jarvis told cheering Stein members after her first-ballot victory. "I predict that the Gertrude Stein Club has once again identified the next mayor."

Jarvis, who has trailed most of the other candidates in public opinion polls, said in an interview that the Stein endorsement will "mean the momentum that this campaign needs."

The gay vote has become one of the most sought-after voting blocs in D.C. politics in recent years, not only because of the large number of gay people living in the District -- an estimated 60,000 -- but also because of their active participation in the political process.

Barry has long been the community's favorite local politician, and in fact, until last night, Stein had never endorsed another candidate for mayor.

Stein President Mauro Montoya said that Barry, who is expected shortly to take himself out of the mayor's race, asked that his name not be considered last night.

Jarvis has assiduously courted the gay vote in the current campaign, showing up frequently at gay events and supporting a variety of causes supported by AIDS activists, from increased funding for AIDS services to support for legislation giving gay partners the same employment benefits as married partners.

Christine Riddiough, a former Stein president who spoke on Jarvis's behalf last night, said that Jarvis has been a leader on gay and lesbian issues, and she urged her colleagues to help stop Ray's candidacy, which has been doing well in the polls.

Ray angered some gay activists several weeks ago when he appeared before the D.C. Gay and Lesbian Activists Alliance and advocated heterosexuality for the black community.

"He will clearly not be a leader," said Riddiough, a Barry appointee to the Alcoholic Beverage Control Board. "He's very influenced by conservative forces that tend to be anti-gay . . . . We need to stand up now."

In a debate before the club voted, Ray told club members that "you will have a friend in John Ray . . . who will stand up for human rights." He said his record on gay issues is "second to none."