|Mr Khan said:
The claim is that they are not the same. Being related to someone provides the legal framework that marriage in turn provides making the legal framework unnecessary, and thus is not needed. The issues surrounding polygamy are distinct from the issues surrounding gay marriage, polygamy being an artifact of an older era and historically exploitative towards one gender.
With marriage we have an institution which is a legal framework that provides individuals with certain benefits. What we must debate on the matter of gay marriage then is that certain couples are being denied the ability to enter into this contract, who otherwise need to do so.
As I stated above, "Polygamy is not okay because it creates inherently unequal partnerships. For example, situations where multiple women have to share one man." That argument DOES NOT apply to same-sex marriage. Therefore, same-sex marriage and polygamy are logically and ethically different. I can support same-sex marriage without also supporting polygamy.
Here's an affirmative statement of my position: In my view, two people should be allowed to marry as long as (1) they are both consenting adults, (2) their marriage would create an equal partnership, and (3) their marriage would not put their children at substantial risk for a negative outcome that is not shared by the parents.
Same-sex marriage would pass this test. Polygamy would fail, due to criterion (2), and same-family marriage would fail due to criterion (3).