I do not support the Defense of Marriage Act or any other laws banning same sex marriage because the government has no business legislating morals or religious principles. I can't impose my views of marriage on others any more than I can impose baptism, prayer, or Bible reading on them.
However, I firmly believe that following close behind legalisation of same sex marriage will be discrimination charges targeting any clergy who refuses to perform such weddings on demand. The State of California is already going after businesses such as photographers and cake shops for turning away same sex couples. Gays shouldn't have a right to force participation in something a person believes is a sin. I don't know if the first case will be somebody who truly wants a church wedding or somebody who wants to start a test case but the possibilities trouble me and for this reason anyone expecting my libertarian leanings to push me into full support of their lifestyle will be disappointed.