Why are so many voters opposed to same sex marriage, while generally in favor of granting same-sex couples all the rights inherent to marriage?

Richard Thompson Ford, over at Slate, makes a fairly compelling argument: It's all about the desire to have someone at home cooking you dinner and cleaning up the house on the part of elderly and conservative voters.

After all, traditional marriage isn't just analogous to sex discrimination—it is sex discrimination: Only men may marry women, and only women may marry men. Same-sex marriage would transform an institution that currently defines two distinctive sex roles—husband and wife—by replacing those different halves with one sex-neutral role—spouse. Sure, we could call two married men "husbands" and two married women "wives," but the specific role for each sex that now defines marriage would be lost. Widespread opposition to same-sex marriage might reflect a desire to hang on to these distinctive sex roles rather than vicious anti-gay bigotry.

(For the record, I cook, do laundry and clean up for my girlfriend already. If I depended upon her to do so—fulfilling traditional gender roles—I would be hungry, naked and living in filth.)