The shortcoming of statistics is that, when all is said and done, they are just numbers. What about divorces that result in one or both of the people getting happily re-married, rather than remaining in a miserable marriage? I know of several (my mother) such cases. Which kids have fewer social pathologies - those who grow up in a household where parents have "strong" marriages or those who grow up in a household where the parents have "weak" marriages?
"we can trust the government to uphold that standard because no people has ever voted for homosexual marriage. Even now, it is being imposed by courts."
Are the courts not part of the government?
"In a democratic republic, the people can, and must be, trusted to guard their social institutions."
Why the insistence that they use government in this endeavor?
Government must be involved in marriage.
At the start of this nation, marriage was only recorded in a non-uniform means. church records were not reliable and inconsistent. Additionally people went to the courts to disolve a marriage with only a church record to prove a marriage.
Thus the governement has to have the central role of record keeper. A license is just a recording and a means on making sure those that marry are legally able.
Laws such as inheritance, incompetency, medical surrogacy are all dependent on a consitent and uniform rule of marriage.
Additionally as a society we reward the insitution not the individual. Marriage is about promoting the insititution which proliferates the society for future generations. Homosexuality only proliferates recreational sex.