At the end of the day, it's purely black and white. The religious right tries to invent a gray area, but there really isn't, nor should there be.
Marriage is a legal contract between two consenting adults. This is a fact. That being said, there's no conceivable secular reason to oppose same sex marriage on a purely political level. You can rant about the traditional family and the values America was founded on, but none of them are effected in the slightest by the existence of same-sex marriage.
No matter how much you may protest, an opposition to same-sex marriage on a legal level is pure unadulterated bigotry in every sense of the word, and inventing your own definitions of bigotry doesn't make that any less true.
If you don't want to support same-sex marriage, then be my guest. But don't deny people rights. If a clergyman doesn't want to perform a same-sex marriage ceremony, then that is THEIR RIGHT. Nobody cares to force clergy to perform ceremonies that go against their beliefs. All that is asked is that the plethora of clergy who are willing to (or the complete absence of clergy altogether), be permitted to proceed without legal opposition, and given the nature of the constitution, there shouldn't be any opposition.