The argument that gay marriage does not lead to polygamy is absurd. Every argument put forth on behalf of gay marriage (equality etc...) also applies to polygamy and incest. If you support gay marriage, you are logically and morally bound to support polygamy.
All relationships between consenting adults are deserving of marriage
Gay relationships are relationships between consenting adults
Therefore, gay relationships are deserving of marriage
All C is D
G is C
G is D
Substitute polygamy and incest for gay relationships and the logic still applies.
I don't see how they can legitimize incest, as it can create physically and intellectually challenged children. Of course, there's always abortion, right?
Sorry.
Homosexuality was soundly condemned by God in the Bible; polygamy was not.
Then again, if you don't believe in God or the Bible, then your logic might fit...for you.
In principle you are correct. However, people who support gay marriage are neither logical nor moral, so unfortunately they won't feel bound by either.
Not a good example because you can add hetrosexual and it works too. So you are allowing ALL of them to work. Don't add to the acceptance.
except that incest has the procreation problem. that's the only big difference between the others. but just to play devil's advocate, why would you care if a brother and sister got married if they couldn't have kids? i have a hard time seeing the problem there.