The Supreme Court in Dredd Scott made black people less than white people, it was the Supreme Court that overturned itself and reinstated their rights.
It was the 13th amendment that gave blacks rights.
I find the idea that gay people have to prove that they deserve equality is not only disturbing, but also a dangerous precedent to set. Who will be next to have to prove they are worthy of equality? Equality should not be a popularity contest.
Again, gays can marry in every state, just like heteros. They are equal. They want to change the definition of marriage using the language of civil rights as a smoke screen. The burden is on them to convince a majority to support this new concept. And in a democracy, yes--it is majority rule. If you don't believe in the general good will of the majority of your neighbors, then you are a fool to support it.