You know that the studies you are basing your assertions on are invalidated as having sample sizes too small, study periods too short and research methods that were clearly unscientific.The fact that children can do as well with same sex parents does not "negate the power of blood relationships". It only shows that is not the only relationship that can be valuable and result in success.
"But even if Congress believed at the time of DOMA's passage that children had the best chance at success if raised jointly by their biological mothers and fathers, a desire to encourage heterosexual couples to procreate and rear their own children more responsibly would not provide a rational basis for denying federal recognition to same-sex marriages. Such denial does nothing to promote stability in heterosexual parenting. Rather, it "prevents children of same-sex couples from enjoying the immeasurable advantages that flow from the assurance of a stable family structure, when afforded equal recognition under federal law." (Gill)
You negate blood relations by equating them with a relationship that duplicates one gender, eliminates another and is absent at least one biological parent.