"I don't think the argument for gay rights should hinge on whether you're gay or you know someone who is gay."

"If something is actually bad or morally wrong, you don't try to promote it by talking about the person in your family who does it. You may notice that I've been writing in support of same-sex marriage on this blog for more than 7 years, and I don't think I've ever bolstered the argument with anecdotes of personal experience. In fact, I think it cheapens the argument to blend that in."

That's what I wrote in September 2011, back when Dick Cheney clearly stated his support for same-sex marriage. A reader emailed me that in connection with Obama's statement about same-sex marriage, which was thoroughly bolstered with references to the real people he knows:

I've thought about members of my staff in long-term, committed, same-sex relationships who are raising kids together. Through our efforts to end the "Don't Ask, Don't Tell" policy, I've gotten to know some of the gay and lesbian troops who are serving our country with honor and distinction....

Even at my own dinner table, when I look at Sasha and Malia, who have friends whose parents are same-sex couples, I know it wouldn't dawn on them that their friends' parents should be treated differently.

Do our moral values take shape around the activities of the people we happen to know?