This refers to:
I believe myself to be rational when I say that in one category the sexual coupling can sometimes result in procreation, but in the other category, the sexual coupling can never result in procreation. -NutCrackerBoy, 408
What I was saying was that the main purpose of marriage (from the point of view of the state) is to regulate the ramifications of procreation and that is a very rational reason to define the institution as the union of one man and one woman - the same way it has been defined in church and civilization since antiquity. But you asked something different. Let me take two iterations to rephrase your question. You tell me if by doing so its sense is lost.
Rephrase #1: If lawmakers acting on our behalf (or activist judges) redefine marriage so that marriage licenses are issued to same-sex couples, how will it diminish the ability of heterosexual couples to procreate?
Rephrase #2: How will marriage licenses being issued to same-sex couples diminish the effectiveness of marriage from its main purpose - to regulate the ramifications of procreation.
I think this is a reasonable (after the rephrasing) question. My answer is two-fold:
1. Litigation will begin at once to change the legal structures of marriage to better accomodate same-sex couples. These changes will be impossible to resist if the equal protection argument holds sway. Marriage will be transformed into something different. Something that by definition has nothing to do with procreation.
2. It is just illogical to include a class which never procreates into a legal status whose main purpose has to do with procreation.
My God man, but you are thick!
Here's a news flash!!!
Procreation can be achieved by same sex couples!!!!!