And this underlines why the natural family MUST be defended in purely natural terms, without reference to supernaturally revealed/Scriptural truths, which are valuable for me (a believer) but should not be the center of any argument concerning public policy.
Social science research across the board shows that the best outcomes for children are correlated with living with their married, natural father and mother in a stable, low-conflict household.
Even children separated from their natural parents (e.g. displaced refugees, abandoned children, adopted children), derive an important sense of identity from their natural fathers (cf. the long-term "Who am I?" quest of Barack Obama, Jr.); fatherhood is neither optional nor redundant. Children likewise require their parents for 18 years and beyond.
Therefore promotion of this particular arrangement, above all others, is not a matter of bias or invidious discrimination, but is a hallmark of sound public policy.
If marriage is to be replaced by legal recognition of domestic partnership only, there is no reason why any house-sharing, whether between a mother and her adult son, two elderly sisters, a wealthy widow and her resident chef, chauffeur, and Feng Shui consultant --- or any number of housemates, should not qualify for "domestic partner" perks: but then, what's the point?
Why should people who merely live together, be licensed by the State and, in net effect, subsidized by people who don't live together? Where is the public interest?
Quite frankly it's none of their damned business. No State should be charging a fee or 'legally' recognizing any relationship between consenting adults.
There's no Constitutional basis for that anywhere.
Anyone who wants to marry in any Church should be free to do so without having to pay one thin dime to the State.
Get the State entirely OUT of the business of 'recognizing' any interpersonal relationship between consenting adults.
Period.
L