A commonly cited argument, to be sure. Let's look at the magnitude of its impact in practice. Per federal statistics, roughly five hundred thousand US children are in foster care, which is roughly two-thirds of a percent of children in the US, or six per thousand. Figures on the number of children adopted by homosexual couples are somewhat harder to come by, but the highest number I found cited by a pro- group calls it about 22,000, which works out to about 4.4 percent of children in care, or 26 per hundred thousand of all children in the US.
Does this benefit seem likely to outweigh the cost to the other 99,974 children and their families? Does it justify a federal transfer of wealth from those families - who, given the fashion by which the tax benefits we discuss are distributed, will tend toward the lower end of the income scale - to those homosexual couples already wealthy enough to consider adoption and be likely to gain approval?
There's an argument to be made that these figures aren't representative because homosexual marriage is so new, and will increase over time, and that's fair. Let's look at the best possible case. Roughly 1.5 percent of the US population identifies as homosexual. (We disregard self-identified bisexuals in this analysis; when they make up their minds, they all but unanimously settle on heterosexualism.) Out of call it 240 hundred million Americans, if every two homosexuals equate to one marriage, we have 1.8 million couples. With half a million children in care, to reach full coverage, the overall adoption rate among those couples needs to be a bit more than one in four.
Does this seem likely? That's four orders of magnitude, and roughly a factor of three thousand, over the general adoption rate - and if we disregard intercountry adoptions, as we have throughout this discussion and properly should here, it becomes more like a factor of five thousand.
I do not dispute that homosexual couples, unable themselves to produce children absent extensive scientific and medical intervention, are more likely than others to adopt. But five thousand times more likely?