Not sure how that example aids your point. I hold anyone in contempt who seeks to abrogate the rights of an entire group of people. Such ignorant reactionary behavior deserves little else but contempt.
When someone says "the great unwashed" shouldn't get to vote, I think that's one hell of a lot more arrogant than saying "those who did vote for divisive and unnecessary scaremongering like Prop 8 are contemptuous". At least the latter aren't claiming that they should be disenfranchised for voting for a choice unfavorable to them.