Earlier quoted context omitted.
I think they summarise their arguments themselves. For example "Although the policy arguments for extending marriage to same-sex couples may be compelling, the legal arguments for requiring such an extension are not. The fundamental right to marry does not include a right to make a State change its definition of marriage. And a State’s decision to maintain the meaning of marriage that has persisted in every culture t…
Considering there are plenty of examples of "gay" marriage from thousands of years ago, calling strait marriage traditional seems factually incorrect. Edit: http://www.catholicworldreport.com/Item/1367/gay_marriagenot...
That is not true. There are examples in Western Civilization of the acceptance of some homosexual behavior, but not of same sex marriage.
Not even Roman Emperor Hadrian was able to marry his lover.