I can't see anything legally wrong with same-sex marriage, but I believe that marriage between a man and a woman is ordained of God so I can't support same-sex marriage either. I believe that families are happiest when founded upon the teachings of Jesus Christ. For more information on strengthening the family, read “The Family: A Proclamation to the World” at lds.org. Here's the link:
http://lds.org/ldsorg/v/index.jsp?vgnextoid=e1fa5f74db46c010VgnVCM1000004d82620aRCRD&locale=0&sourceId=1aba862384d20110VgnVCM100000176f620a____&hideNav=1&contentLocale=0