The walls of The Eagle, a "leather" gay bar on Washington's Ninth Street NW, were decorated with motorcycle medallions and pictures of blue jeaned cowboys and evil-looking motorcycle toughs.

'But the gays who normally come there to drink beer in their leather jackets were wearing coats and ties instead on this hot July evening. And in their midst, wearing a conservative business suit with his wife at his side, stood mayoral candidate Marion Barry, shaking hands, looking for a few votes.

The 50-plus gays, mostly white and mostly male, had each paid $50 to come to the fund-raiser where they could chat with Barry and eat beef Wellington and french-style green beans.

Gay rights in not a dominant issue in the Sept. 12 Democratic primary, but for Barry, who trails his two chief rivals, Mayor Walter E. Washington and City Council Chairman Sterling Tucker, every vote is crucial. Washington's gay community is substantial, with 10 percent of the population - or 60,000 residents - estimated to be homosexual, according to a gay activist.

"In this election, because of the nature of the participation by Tucker, Washington and myself, I need every vote I can get from everybody," Barry said last week. "I have attracted groups of people into my candidacy, including gay activists. They are going to get as many votes as they can, but it's hard to gauge how many votes they can bring."

In this close campaign gays who boast a nearly solid voting bloc of several thousand, hope to cast the deciding ballots for Barry.

So far, according to leaders of the politically active Gay Activist Alliance and the Gertrude Stein Democratic Club, gays have raised nearly $14,000 for Barry and $500 for Arrington Dixon, who they believe is mostly likely to win the council chairman's race beating the anti-gay candidate Douglas Moore.

Ivanhoe Donaldson, Barry's campaign manager, said several prominent gay activists are advisers to Barry's campaign as well.

Volunteers from those clubs have manned phone bans, calling uncommitted voters to ask them to support Barry, as well as passing out literature.

Richard Maulsby, one of the cofounders of the Gertrude Stein Democratic Club, said about 100 volunteers will work for Barry and others on election day as poll watchers as well.

Gay activist leaders said their groups have registered nearly 4,000 new voters through gay literature, which candidates favor gay rights.

For the first time, too, activists have enlisted the support of owners of gay businesses, which have traditionally been outside the mainstream of activism.

Don Bruce, part-owner of The Eagle, said "I think we have a political stake in the government, and it's time we (as business owners) got started in exercising our rights. Money is as appropriate as the vote (in influencing candidates). We support Barry because he has shown support for our businesses as well as for gays."

Bruce said The Eagle fund-raiser provided $3,000 to Barry's campaign. Another fund-raiser Wednesday at the gay-oriented Pier 9 disco, sponsored by owners of the Lost and Found and the Pier 9, has a goal of $5,000 - all of which will go to Barry's campaign.

Gay political activism has grown a great deal since its infancy in the early 1970s.

"Back in the '60s, it was assumed that no politician would want our support because it would be a kiss of death," said Frank Kameny, who gay activists here call the father of the gay movement in Washington.

"Public officials here were extremely uncomfortable with gay issue and when they would talk to us, they said they didn't want to support us openly because they felt they would lose more support than they would gain," said Kameny, the first gay in the country to run openly as a homosexual for political office - he ran for the city's congressional delegate seat in 1971.

Kameny and other leaders said that through the years, gays have learned lessons in a political courtship of local politicians, including Washingtons, Tucker and Barry.

Gays have successfully approached Mayor Washington to appoint the first openly gay person to a commission in 1971 - Kameny - got the school board, led by Barry in 1972, to pass a resolution prohibiting discrimination based on sexual preference in public school system hiring and, most recently, persuaded members of the City Council, including John Wilson, (D-Ward 2), Nadine Winter (D-Ward 6), Polly Shackleton (D-Ward 3), Barry (D-At Large) and council chairman Tucker to support Gay Pride Day and other gay-oriented issues for several years.

But gay activist groups, whose members are mostly white, have not been able to attract the large number of black gays in the District who have refused to become a visible part of the local gay effort.

Nonetheless, a four-month-old group of black gays has endorsed Tucker because, members say, they are leery of Barry's political ties to white gay activists.

Other candidates are, willingly or otherwise, benefited from gay support, too.

"Every candidate I know of, has some member of my club (the Saturday night mostly gay crowd) on their campaign committees," said Aundrea Scott, co-owner of the Clubhouse a disco that becomes gay on Saturday nights. "They may not know that these people are gay, but they don't need to know, right? No matter who wins, black gays are going to have some influence in this city. If you want to call gay kids spies, then we have spies in every camp."