Reuters:

The Michigan defense of its same-sex marriage ban got off to a rough start on Monday when its first witness at a federal trial was dismissed for not being qualified, dealing a blow in what may be an uphill battle to keep its law on the books.... In opposing gay marriage, Michigan has focused on the well-being of children, arguing that their interests are best served by having both a father and a mother, a position dismissed by gay rights advocates and their allies.

This gay rights advocate wants to go on the record: moms and dads are great! I had a mom and a dad and they were great! But kids don't need a mom and a dad to thrive. They need loving, competent parents. Acknowledging this fact takes nothing away from the awesomeness of good, fit, capable, loving, married moms and dads who are raising their own biological children. But acknowledging their awesomeness shouldn't take anything away from same-sex parents, straight adoptive parents, or single parents. Parental awesomeness isn't a zero-sum game. There's plenty of awesomeness to go around.

But let's pretend for a second that Michigan's argument against same-sex marriage is both legit from a social-science POV (which it's not) and completely and totally sincere.

If Michigan believes that children have a right to be raised by their married biological moms and dads... why is it legal in Michigan for straight couples with small children to divorce? Why is it legal for single people to adopt children in Michigan? Why is it legal for single women to undergo IVF in Michigan? Men who get women pregnant in Michigan are not legally obligated to marry the mothers of their children and single women in Michigan who get pregnant are not legally obligated to marry the fathers of their children. Michigan wants to see children raised by their biological moms and dads but the state only penalizes same-sex couples—and most same-sex couples do not have children, most have no plans to have children, and same-sex couples never have children by accident.

And there's this: banning gay marriage doesn't prevent same-sex couples who want to have kids from becoming parents through IVF, adoption, and informal co-parenting arrangements. Banning same-sex marriage only prevents loving, same-sex couples from marrying. It also harms the well-being of children who are already being raised by same-sex parents.

So even if we were to accept Michigan's premise—that kids with gay parents are somehow disadvantaged (and the evidence says they're not)—you have to ask why the state doesn't prevent the kinds of straight marriages that disadvantage kids (don't let the poors marry) or prevent the kinds of straight parenting (single parents, divorced parents, remarried parents) that disadvantage kids. And there's only one answer to that question: Michigan's ban on gay marriage isn't about kids at all. It's about anti-gay bigotry.

UPDATE: Mark Regnerus—author of an infamous and discredited study financed by anti-gay groups and cited by haters around the world—was called as an "expert witness" by the state of Michigan. Regnerus is being cross-examined today. Amy Lang and Steve Friess are doing an amazing job live-tweeting Regnerus's testimony right now. After years of seeing Regnerus's pseudo science cited by everyone from the American bigots who financed it to Catholic bishops to Russian homophobes to murderous Ugandan bigots, seeing this vile, hateful, bigoted liar confronted under oath is just too delicious.

UPDATE 2: John Corvino dismantled Regnerus's study in this video...