It's bizarre that this thread is getting so much attention, which is why it actually did draw my attention.
After reading through here, I'd just like to note that being against the legalization of gay marriage has nothing to do with opinion, it has to do with your beliefs. Opinions are drawn on facts, beliefs are drawn on morals/faith/values. Sadly, some of the posts in here fall into yet a third category.. prejudice. I'm making a decision to not address that third category.
Anyway, there is nothing wrong with having personal beliefs. It is Mary's belief that marriage is a sacred thing. That's a cultural/religious decision to her. However, the term marriage is a very loose term. To literally redefine a word that will only be valid in the United States (technically only in states which it has been redefined) is a bit of an outlandish task.... right up there with removing the title of "Planet" from pluto, but at least the rest of the world accepted that one.
Thing is, marriage has so many meanings across the world. In Africa, there are cultures where you can marry a ghost, or a cow... It's a word. It is not sacred.
Then there is the idea of a holy union which also is called a marriage. This is where the uproar comes from. Stating you do not think gay people should be able to be "married" because it shares a reference with the idea of the "holy union" borders on the edge of prejudice.
There are religious institutions that are not opposed to homosexuality and that would accept gay couples in allowing them and enabling them to be married within their religious facility. No one is forcing these institutions to allow these marriages.
It is perfectly acceptable to have a belief in which you feel it is opposed to your religion for a gay couple to be wed, but it is not against every religious sect's belief system. So by opposing the allowance of same sex marriages, you are opposing the beliefs of others.
Fortunately, the way our government is meant to work is majority rules, but with minority rights. The homosexual community is in the minority, and the state governments are more and more beginning to grant homosexuals the rights to the same benefits as married couples as well as allowing religious institutions to make the decision as to whether or not they approve or disapprove of the union.
Mary is entitled to her beliefs, even if they don't coincide with how our government is meant to respond.