I participated in the forums discussions about Prop 8 at the time.
From that I have a hunch that most people who oppose same-sex marriage would not admit to hating gay people. It is fear of change, not all-out hate, that motivates them.
To a degree that is a good thing. Hate is hard to remove. Fear of change, not as much.
It seems to me that the core of the troubles involving SSM are born out of the dificulty of dialog between conservatives and freedom advocates. Far too many people sincerely believe homosexuality to be something inherently wrong, to be "cured" or at least hidden.
One of the consequences of that mistake is that they unconsciously expect homosexuals to be ashamed of who they are, as if they were criminals. There is no way to overcome that sorry situation except by winning the hearts and minds of those who fear homosexual people. Dialog should be nurtured, for it is the only way of dissolving the fear of change that currently scares the proponents and supporters of Prop 8 and similar initiatives.
The bottom line is that I don't think this is much of a legal matter, despite superficial appearances. The challenge is still and above all else primarily one of social integration, and can only be solved at that level. Once enough conservatives realize that Same Sex Marriage is no more of a threat than, say, ponytails in males, the resistance will vanish, I'm certain of it.