you may be interested to know, my relationship does not lead to incest

We are connecting with Our Family Coalition, an organization that advocates for and assists LGBT families in the Bay Area. They put out a resource guide to LGBT-family-friendly services. They recently sent a rescindment of their endorsement of a local pediatrician because she signed a "Yes on 8" argument in the mass-mailed California Voter Guide. [Prop 8 is a proposed amendment to the California constitution that says "Only marriage between a man and a woman is valid or recognized in California."]. OFC sent a letter to this doctor, and here are excerpts of her reply (and my response):

"I am hoping that my gay/lesbian families -who I so appreciate and enjoy caring for - will realize that there is a difference between allowing gays/lesbians to form families and adopt children without terming this a marriage. Because of the judges' ruling, there would be no religious exclusion allowed - churches may be forced to marry couples in disagreement with their church doctrine. I am also concerned that this ruling actually opens the door to other relationships (such as polygamy, incest) that may not be in the best interest of children."
"I trust you have seen the love and care that I have demonstrated to you, as I have to all my families without regard for who constitutes the family. I have always attempted to keep my public policy concerns separated from the medical care I provide."

Dear Dr. ---,
I understand that you provide adequate care for your clients, no matter what their family status. I also believe that you truly appreciate your customers. I do question your ability to keep public policy concerns separate from the medical care you provide. How can you provide an adequately caring environment when you seem to believe that the parents of some of your clients are less legitimate than others--that their families are somehow not quite real.
But that aside, I have two bigger disagreements. First of all, no one forces a church to marry anyone. The church, like any provider of a service, has the right to refuse to provide service. And frankly, I support the church's right to discriminate in this case. I would challenge the church on theological and Biblical grounds, but it's really no skin off my back if your church doesn't approve of my relationship within its walls and authority. But that doesn't give your church a right to enforce its beliefs in a civil context, especially when there is no single religious or Christian view on same-sex marriages.
But let me tell you what really steams me: You imply that my right to marry my partner somehow paves the way for incest. You don't know me. But if you did, you'd see that nothing about my loving, consensual, caring relationship connects with incest. In fact, if I take your argument seriously, incest would be legal under the proposed amendment--as long as the couple is a man and a woman. Given the long battle of recognition of same-sex relationships in the US, I'm surprised that you think it's plausible that same-sex marriage somehow is "closer" to incest. I don't have the statistics on me, but I believe that most incest is committed by heterosexual men. I do know at least one kid who grew up in a polyamorous household, and she's actually one of the better adjusted women I've met. You do realize that in our Christian Bible, polygamy was quite common in ancient Hebrew cultures. And aside from Jacob and Esau's quarrels and King David's sons' craziness, I don't recall any kids being seriously messed up by polyamory. And actually I think in both their cases, the conflict was more about land, money, and acension to the throne. Maybe we should create a constitutional amendment unrecognizing inheritance. Sorry, I'm being silly.
I think I can see your logic, even if I don't agree with it: somehow same-sex relationships are somehow more sinful or "wrong" than heterosexual relationships, and it is some kind of slippery slope from there to incest. That's really twisted thinking. Like assuming that if we admit women into the medical field, then somehow that's a slippery slope to letting children and animals become doctors.
I do appreciate your willingness to go public with your opinions, and I hope you are equally willing to hear from some of the gay and lesbian parents of your clients.
Sincerely,
Wade