SUNDAY'S 300,000-strong gathering in Washington DC was the biggest coming out party the American gay community has thrown. Part-protest but mainly celebration, the march through the capital was a statement of purpose: ''We are here,'' the event proclaimed, ''and we are going to fight for our interests and our rights.'' What was heralded by many - including virtually every major newspaper - as a positive milestone for gay rights, however, was seen by others as a dire threat to the American way of life. For the increasingly organised Christian right, homosexuality is both a symptom and a cause of social decay, and its creeping legitimacy a morally urgent call-to-arms. Indeed, combating the ''homosexual agenda'' has supplanted abortion as the main focal point of a conservative, grass-roots political movement that is quietly putting people in office across the land. Like abortion, there is no room for tolerance: ''It's not diversity,'' read an anti-gay poster on Sunday, ''it's perversity.'' As battle lines are drawn, it becomes apparent that a rough symmetry exists between these two hostile camps. Gay activists and the Christian right have each developed effective political lobbies, both locally and nationally. Their principal organisations, and the populations they represent, are comparable in size. Likewise their representation in Congress, where there are two openly gay members and others sympathetic to gay issues on one side of the aisle, and several ultra-conservative Christians and their supporters on the other. Indeed, each group holds a similar degree of influence in mainstream politics. The far right's grip on the Republican Party became obvious - painfully so to moderate Republicans - at last year's National Convention, where Pat Buchanan and televangelist Pat Robertson demonised homosexuals and called for a ''holy war'' to ''recapture the soul of America''. It may have cost George Bush the election, but it proved how powerful the anti-gay crusaders are. Gay advocates are no less influential in Democratic politics. They contributed heavily to Bill Clinton's campaign, and play a significant role in the municipal politics of virtually every large city in the country. Mr Clinton, bruised by criticism of hisplan to lift the ban on gays in the military, distanced himself from Sunday's march by leaving town and offering only a second-hand message of support. But no one doubts that such retreats are only tactical. Both camps have successfully backed local and state measures, some protecting gays from discrimination, others preventing such anti-discrimination measures from being enacted. In New York City, the Christian Coalition - whose motto is Think Like Jesus, Fight like David, Lead like Moses, Run like Lincoln - has forged an unusual alliance with the Catholic Church to promote conservative candidates for the city's 32 school boards, and to oppose sex education, condom distribution and the city's policy of teaching tolerance toward gays. The fact that gay activists saw last weekend's event as a successor to the famous 1963 march that helped usher in landmark civil rights legislation is part of a subtle but profound change in the gay community's self-perception and public relations strategy, a shift that might backfire, at least in the short term. There are two facets of this shift. Somewhere along the road of gay rights activism, ''sexual preference'' gave way to ''sexual orientation''. The difference, and its implications, are enormous. The first term suggests free will, what Dan Quayle might have derisively called a ''lifestyle choice''. Whether that choice is dictated by nature is irrelevant, even if true. Preference means doing what one wants. These days, gay men and women are more likely to say they are homosexuals not by choice but by design. This biological determinism has become the unspoken basis for demanding special civil rights legislation: being homosexual, the argument goes, is the same as being black or being a woman - a physiological fact. The problem with this claim is twofold. First, science has yet to conclude that homosexuality is more biological than psychological. Even if true, however, staking one's claim to equal social status on this fact implicitly weakens one's position. Insteadof proclaiming, ''I am gay because I want to be,'' one is saying, ''I am gay because I can't help it.'' The second, and related, shift is from vive la difference to conformity. As the gay movement gains wider acceptance, its leadership has tried hard to ''look like the rest of America'', in the words of Torie Osborn, executive director of the National Gay and Lesbian Task Force. The aim, it seems, it to pose less of a threatening image to a middle America for whom homosexuality is synonymous with bun-hugging leather and horse whips. The problem here is that homosexuals are not like America, they are part of America. What, in other words, is wrong with leather? It may not be for you or me - or most gays, for that matter - but by what right do we forbid such pleasures? Again, the new logic seems to narrow, rather than expand, gay rights. Rather than saying, ''I'm different and if you don't like it that's your problem,'' one is left to say, ''See? I'm not as bad as you thought - in fact I'm almost the same as you.'' Howboring.