One of the primary reasons Prop 8 was passed here in Cali was in large part do to the very deceptive television ad campagin that was waged.
In particular one ad in which showed an elementary school child coming home and proclaiming to his mother "look mom what I learned in school today", hence proclaiming the fact that gay marriage would be taught to young children in school, which was a lie. This was a malicious attack in a very very hard fought campaign. It's not over though, there will be litigation in the California supreme court, and as well as SF's mayor Gavin Newsom will most likely run for California Governor in the next term, and in the even he wins' I'd say we see this issue again.
And someone mentioned the large Black and Latino/Hispanic turnout which propagated this passage, that is not entirely correct. California has some very large conservative counties including Orange, Riverside, San Diego as well as the Central Valley which went against the proposition. It is true that most Blacks voted for the proposition, however as to Latinos, they are more liberal the younger they get. Only the older generations tend to have conservative viewpoints, and even then they are more liberal than the John McCain voting crazies.