Damn, Clone, your ability to take someone's words out of context, construct a different intended purpose/meaning for those words, then dispute it, is amazing.
But, in short, I'll address each. It's debatable whether one's sexual orientation is an "immutable characteristic". I know several formerly gay people. I know one guy who was formerly gay, then married a lady (divorced), then gay again, then married again (to a different woman), now divorced but dating the woman he married first. Maybe he's just confused. He's told me that "sometimes I just feel gay, sometimes I don't".
There was no subtle implication. I just noted that many African Americans do not equate their fight for civil rights with that of gays.
It wasn't that long before my time. My high school was the first integrated high school in my home state. I would not say I "lived it" but I observed African Americans' fight from a pretty good viewpoint.
I disagree one is an immutable characteristic and the other is not. Allowing polygamy would not bother me any more than allowing gay marriage.
I doubt it would bother me if the state decided my marriage was invalid for some reason. I value the sacrament of marriage in my faith far more than the legal recognition from the state.