if we consider that it has impicated the right to adopt or constitute family with children. I for one won't put the welfare of a child after political correctness and what I consider to be selfish exigencies of a vocal group. A child without parents of both sexes is (in here, at least) very, very likely to be harassed and bullied at school, most will never feel accepted.
Which is worse, having two loving parents (unlike some biological parents, people who go to the trouble of adopting children--and it is a lot of trouble, and generally very expensive--always want them badly) or being an orphan? To the extent that same-sex couples help reduce the number of children with no parents, I'd say they're providing a great benefit to the world.
There are also a large number of children living with only one parent; more than 25% of families in the U.S. are in this situation. Is having two parents of the same sex worse than having only one parent?
True, not all children of same-sex couples are adopted. More and more frequently, such couples are having biological children, with the help of a donor. But are such children worse off than children of heterosexual couples? Many studies suggest no:http://www.huffingtonpost.co.uk/2013/06/05/gay-couples-children-happier_n_3388498.htmlhttp://www.bu.edu/today/2013/gay-parents-as-good-as-straight-ones/http://www.npr.org/2013/03/22/175014380/children-of-gay-parents-support-same-sex-marriage
I have to wonder if you're just using the welfare of the children as an excuse. I don't doubt some kids of same-sex couples are discriminated against, but so, once upon a time (and even today, in some places), were children of interracial marriages. The solution to that was/is not to outlaw interracial marriage, but to make it so acceptable that no one cares or even notices.
If kids of same-sex couples are bullied, it's precisely because of the opposition to same-sex marriage that these new laws are trying to overcome. By opposing gay marriage on the grounds of hardship to kids, you, it seems to me, are yourself being bullied into accepting the bigoted views of certain members of society, rather than advocating changing them. It's not unlike opposing gay athletes in sports on the grounds that some of their teammates might not like gays. The proper response to that is not to say, sorry, you can't join the team because you're a problem for some of the players. It's to say that if there is a problem, it's not with you, it's with the players who have these views.
The one legitimate argument I can see here is that children of same-sex couples may miss to some extent having a role model of both sexes. But nuclear families are hardly isolated from such models, which can be provided by relatives, close friends, etc. And families can't necessarily be expected to provide a perfect environment. I grew up with no sisters, and have always felt my understanding of women would have been a little better if this had not been the case. But conversely, my understanding of other men has probably been a little stronger. There can be advantages as well as disadvantages in growing up more exposed to one sex than the other.