Public discussion about American families often assumes the nation is largely made up of married heterosexual couples raising their biological children. Yet less than a quarter of all U.S. households fall into this category. Today’s children may be raised by grandparents, single parents, step-parents, aunts, uncles, or foster parents. Their parents may be married or unmarried. They also may be heterosexual or lesbian, gay, bisexual, or transgender—LGBT.[1]
Unfortunately, public policy has not kept up with the changing reality of the American family. Indeed, our laws and discourse largely ignore the roughly 2 million children being raised by LGBT parents. They also ignore children in other family configurations, such as those with unmarried heterosexual parents. As a result, most Americans are probably unaware of the many ways in which unequal treatment and social stigma harm the millions of children whose families do not fit into a certain mold.
http://www.americanprogress.org/issues/2011/10/all_children_matter.html