I suspect that African Americans would still not have equal rights in the United States had the decision been left in the hands of the electorate. Am I saying that Americans in general are racist and homophobic? Yes, I guess I am, though that situation is changing slowly, thanks in some part to the Supreme Court and certain white Democratic leaders sympathetic to the cause of civil rights back in the 1960s. A government that recognizes the equality of its citizens contributes significantly to move people's attitudes towards equality and fair play.
Did not Martin Luther King Jr. and other civil rights activists do a lot towards that change? Most definitely, yes, mainly in drawing national attention to the plight of black Americans, especially in the South. But attention has been drawn to the situation of gays, lesbians, and bisexuals for some time now (in the media, in marches on Washington, in everyday contact with openly gay friends and relatives, on the blogosphere).
But attention is not enough, apparently. The importance of "image" and protection of that "image" as central to the welfare and tolerance of a diverse society has obviously been exaggerated. I'm now convinced that however many Dr Kings, Cosbys, and Obamas the gay movement, such as it is, can accrue, will never be enough to make up for the absence of legal, enforced Constitutional equality and liberty for all Americans, regardless of their sexual makeups.
On a positive note, even in the dark years of W, the Supreme Court ruled against state sodomy laws, establishing an important precedent in defending gays and lesbians from unjust criminalizing legislation.
Still, with the current composition of the the US Supreme Court and the trepidation of Democrats who have as much power and public support now as they have ever had in my lifetime, it seems unlikely that a change comparable to what blacks achieved in the 1960s is going to happen for gays and lesbians soon. Not for a long, long time.