Marriage is a social INSTITUTION not a "right" or a "privilege".
Marriage is the most sacred union among humans because it's the MOST nurturing for children and thus maybe the most important social pact of critical importance to the survival of the human race.
In my humble opinion, marriage should be protected by a constitutional amendment, mostly because offspring can result from Marriage, Other children as just as fine, but marriage offers a balanced nurturing environment to raise PRODUCTIVE members of society.
In all likelihood, the framers never imagined the madness of early 21th century as illustrated by Stock-trader picks, Kudlow's ever optimistic message and Gay divorce.
Gays are free to take part in civil unions to ensure access to each other in case of hardship / a mechanism by which to share health and pension benefits . If we grant them marriage, what next, they'll ask for the federal government to subsidize KY Gel.
AND there is no "proof" hat homosexuality has any biological footing. Anecdotal evidence is welcome and induces empathy but does not represent enough to rewrite existing laws.
I'm a male and can't understand how other males can't like tits, or a woman's soft skin.