Here's Adam Serwer's latest on gay marriage in D.C. He makes the important point that anti-gay marriage campaigns in the black community, have at once exploited homophobia and racial prejudice. But the gay activists in the District have been able to fight back, not because they've done outreach to the black community, but because they are the black community:
In Washington, D.C., the anti-gay-rights movement attempted to put recognition of same-sex marriages performed in other states to a citywide referendum (it was rejected by the Board of Elections and Ethics) hoping that the city's mostly black population would come out against it. This dynamic may explain why Bishop Harry Jackson, an African American religious leader, has been put forth as the face of the anti-gay-marriage movement.
There's only one problem: The face of LGBT leadership in D.C. is often black. Nationally, anti-gay-rights activists have had a great deal of success in encouraging black voters to oppose gay rights, partially because LGBT rights are seen -- incorrectly -- as a "white issue." But in Washington, D.C., the diverse composition of the marriage-equality movement means that marriage-equality activists don't have to "reach out" to the black community, because they're already part of it. That doesn't mean marriage-equality activists don't face serious obstacles in garnering support among African Americans, but it makes racial divisions harder to exploit. The lesson is clear -- when the marriage-equality movement is integrated, outreach becomes less of an issue.
It must be said that the District is a special case--it's a majority black municipality, that happens to have a long history of social liberalism. This does not mean that it is absent homophobia, as much as it means that you have people there (many of them black) who've been fighting for gay rights for decades. Given D.C.'s makeup, it's very hard to wage that fight and not engage, on some level, with black people.
Regrettably, I can't think of anywhere else like D.C. Atlanta, perhaps? But I don't see gay marriage coming to Georgia for another decade, at least.