Some clarification for those who think that same sex marriage is like rape, incest, bestiality, and polygamy.
Same sex marriage is not equal to the first three for one very basic reason- consent. Rape, incest and bestiality all involve power imbalances where one (or more) people abuse the body of another being without their consent. Period. Gay marriage involves two adults choosing to take on the responsibility of caring for each other legally, financially and medically. Note the adults choosing part. That means they are consenting. Rape victims, children and animals do not or cannot consent to their own abuse.
Now polygamy might seem a bit more sticky. In a perfect world, polygamy would mean that more than two consenting adults agree to share legal, financial and medical responsibility for each other. But unlike other contracts (which is what marriage essentially is) there is no way to set up equal responsibility over a single person between two or more people. Example:
A man has a wife. He wants another one. So he gets one. Wife number two may have consented to be married to the man, but has she also consented to be married to the other wife. Let’s say she moves into the home jointly owned by Wife One and the man. Does she get partial ownership in the house now? If the man dies, does Wife one have a legal responsibility to share the assets she built up with the man over the years that they were married before wife number two came on the scene? What if the man goes into a coma and there is a question over whether to continue life support or to let the man die? What if the wives disagree? Who gets to make that decision? What if it’s not the man, but it’s Wife One who is in the coma? Does Wife Two get to decide to pull the plug?
Countries where polygamy is legal have solved these problems by disallowing women rights to own property or make legal decisions without the agreement of their husbands. We may be a seriously backwards country when it comes to equal rights, but I do not think that we would undo a hundred years of progress to allow polygamy. Especially when it makes things more