it seems like you sort of have a divide in OC between the areas that are more of a population spillover from LA County and the areas that were later developed. The former being more likely to support prop 8 and the latter being in opposition.
Nah, folks who live near the beach have a different state of mind. (Some of those inland areas in the more pro Prop 8 colors were also developed post 1980 in fact.) The beach folks tend to have fewer kids, or no kids at all (the cost per square foot of housing is considerably higher), and are more secular and libertine. And then there is the ethnic factor. For example, it is clear that the Vietnamese are not too fond of gay marriage - even more so than the Hispanics, who nixed it as well.