...(well actually, I don't, but still...), I would point out that his quote
Same-sex unions "reduce marriage to something of a partnership that provides attractive benefits and sexual convenience without an understanding of lifelong commitment."
is actually a pretty accurate description of the concept of marriage already in existence in the eyes of the state. For matters of civil law, marriage is an arrangement that provides for sharing of property and joint responsibility for the caring of children; in the few states that still outlaw "fornication," it also essentially serves as a "license to have sex." But nowhere in civil law is there any requirement of "lifelong committment," merely that an approved plan for division of joint property and the support of any children resulting from the marriage be in place if and when the marriage ends.
Don't believe it? If you're facing a divorce, try arguing in court that the judge should refuse to grant the divorce because the marriage was a contract for a lifelong committment, and that lifelong committment must be enforced. See how long it takes the judge to stop laughing before telling you what you can do with that argument.
The fact is that "marriage" as defined by the state and as defined by one or another religious body, although containing some overlapping elements, are essentially different. One more reason why I firmly believe that the state should grant
only civil unions, whether the couple is gay or straight, and that marriage be a matter for one's faith community alone.