No one, who stops to think just what is the function of marriage, throughout human history, should think of this as a rational issue. Marriage is, and always has been, about sanctifying the creation of the biological family, by the mating of the sexes in procreational activity. Marriage has always been consummated by a procreational act--whether it actually results in a pregnancy is not the point.
Same sex "marriage," is an oxymoron. You cannot have a marriage that can never be consummated, even in theory.
There are a lot of people, out there, who are going to feel very, very foolish, when a brave little boy (figuratively) points out that the Emperor is stark naked.
William Flax