Cerin,
With all due respect, I am not sure how much any of us has to add to this discussion, unless there are new voices with fresh perspectives.
I will just say this:
To call a union of two people of the same gender a "marriage" is a new idea. New ideas are often frightening to people. Many people do not even know any same-sex couples. At the same time, they have grown up dreaming of being a bride or a groom to a heterosexual marriage. This is comfortable and familiar to them. Even when they can theoretically support "equal rights for everyone", they are uncomfortable equating their comfortable, familiar, romantic dream with something they do not know, do not understand, cannot identify with, and have not seen.
Believe it or not, I understand their perspective more than you might realize. I was deeply homophobic as a young teen, in part due to questions about my own sexual orientation, and in part because that is what I had been taught by adults. When more progressive, tolerant college classmates began to sway my perspective, my first step towards non-prejudice was, "Fine, I support equal rights for gay people, but I don't support gay marriage because that would be going too far."
That is where the majority of the country is right now. But, make no mistake, it is a transitional phase born of discomfort with a new idea. As the idea of gay couples marrying becomes comfortable and familiar, allergic reactions to the use of the word "marriage" to describe the committed unions of same-sex couples will steadily decrease. I invite you to come visit my state, Massachusetts, and observe how - in just a year and a half - heterosexuals who hesitated before saying "marriage" to describe legally recognized queer relationships now talk comfortably about their gay friends marrying. I was here in November 2003 for Goodridge, and I have seen the amazingly rapid progress towards comfort with gay marriage in this state. Witness, too, the rapidly dissipating support for an amendment in this state - recently, attempts to put the issue on the ballot before 2008 were defeated.
I'm so proud of this state, and my city, for being the first in the country to demonstrate true goodwill towards all of their citizens, regardless of sexual orientation.
PS Texans would have acted differently than Maine's citizens did yesterday. Their voting has nothing to do with discomfort about a word and everything to do with anti-gay bigotry.