I also think that the big hangup is the "M-word" for many folks. In neighboring state Massachusetts, they have same gender marriages. In Vermont (which was the very first), and now in New Hampshire, we have civil unions whereas the legal rights are the same as they would be for heterosexual couples. Now, I've heard and MAYBE can see some point in the "separate but equal isn't really equal" arguments that are sometimes raised with respect to this topic, but at least it seems about the best compromise that can be achieved in society at this time. I personally don't want the government to define marriage because marriage also has religious meanings and connotations that vary by religion and culture, and I think that the term "marriage" shouldn't be used in that manner - and this may also be a part of what causes such a ruckus.
I have several friends who are gay. Some of those people have been monogamous partners for 2 decades or so. I personally don't see how their lifestyle or the decision they make with respect to their relationships have anything to do with my relationship with my wife, nor do I see how providing them with the same legal benefits that my wife and I have causes any issues or problems with our marriage or how it is construed. "Life, Liberty, and the Pursuit of Happiness" are important terms that our founding fathers put on that first important piece of paper we keep under bullet proof glass in Washington. If another person's way of life does not infringe upon the rights of others, then live and let live, I say.