Religion says it is wrong as a religious ceremony..people are fighting for the civil aspect regarding benefits and insurance and such...
I mean if you are married and you die your wife/family gets what you have...
If you have lived with your partner for 15 years and have adopted 2 kids and then your partner dies, you are screwed, because all that person's things will go to someone else somewhere else...
It causes a lot of issues...I mean we have all kinds of families now, and I say I don't care if the parents are both women, or both men, or both hermaphrodites they should be able to take care of each other just like any other family under the law.