Okay, please, pay attention. Because I am so full of love and tolerance, I'll try to explain this to you even though you won't understand because you're a BIGOT.
Now, this is why we Enlightened Ones won the argument over marriage. A dim-witted religious right-wing whacko (like you) argued, “Marriage is about procreation. Same-sex couples cannot procreate. Therefore, same-sex ‘marriage’ is nonsense.” To which we Enlightened Ones reasonably responded, “Then why does the state give out marriage licenses to obviously sterile couples?” And the right-wing whacko was stymied and threw a conniption fit and started ranting about slippery slopes to polygamy, incest, bestiality, sexual anarchy in the streets, and other such patent nonsense, none of which could convince any but the most blinkered and bigoted judge. So, that's why we won.
We Enlightened ones use an analogous argument for why the presumption of paternity should also attach to same-sex couples. We point out quite reasonably that even if the wife avails herself of an anonymous sperm donor, her husband is still presumed to be the father at birth. Well, lesbian couples are similarly situated. Therefore, there is no reason why the presumption of paternity, now re-named “presumption of parentage” for obvious reasons, should not apply to the female spouse of a woman who gets pregnant by an anonymous sperm donor. No reason at all, except mindless, irrational, hateful bigotry, exactly the kind that swept Adolf Hitler into power in 1933.
But how can this unimpeachable logic apply to a same-sex male couple that must use a surrogate? It has to because the moral imperative of Equality demands it, and if you can't see this, you are OBVIOUSLY impervious to Public Reason and are, therefore, a bigot who should be cast out into the outer darkness, far, far away from the Sweetness and Light that is the Public Square. So, the only way to fulfill our sacred obligation to the dictates of Equality is for the law to treat surrogacy in the same way as it treats anonymous sperm donation, and that in turn requires the recognition of surrogacy contracts. Hence, marriage equality, the March of History, and just basic common decency requires the legalization of commercial surrogacy in all Fifty States.
In sum, if “marriage equality” is to be truly equal--and that means that all the incidents of marriage, including the presumption of paternity/parentage, attach equally to same-sex and opposite-sex couples--then the renting of wombs must be made legal everywhere.
You got that, bigot?!