Nate Silver over at 538 has a post that argues against the assertion that the “Obama voters” (read non-white) were responsible for prop 8’s passage.

At the end of the day, Prop 8’s passage was more a generational matter than a racial one. If nobody over the age of 65 had voted, Prop 8 would have failed by a point or two … The good news for supporters of marriage equity is that — and there’s no polite way to put this — the older voters aren’t going to be around for all that much longer, and they’ll gradually be cycled out and replaced by younger voters who grew up in a more tolerant era. 

Read it and be reassured.