Well as to Prop 8, my grandma supported it because she hates gays.
This was of course, a point of contention with her gay son. He kicked the sign in repeatedly when he would visit.
I tried to discuss it with her, I really did, but there is no getting past bigotry, they're just so sure that they are correct.
So I aimed at the fiscal. My grandpa voted along fiscal lines, if it raised taxes, he voted no. If it didn't disclose where the money came from, he voted no.
I tried to explain to my grandmother that prop. 8 would lead to endless lawsuits until it were either upheld by the supreme court or thrown out, thus making the point moot.
She really didn't care.
This is probably more useful than my personal anecdotes:
http://www.metafilter.com/121033/Windsor-vs-United-States