Before it becomes too obvious, let me note that I'm not a lawyer. So let's make this really simple.
A marriage consists of a man and a woman. Anything else is not a marriage.
If the participants in love, that's good, but not essential - millions of marriages the world over are arranged by others such that the bride and groom have never even met before marriage. Thus love is not relevant.
If they procreate, that's OK, but not essential.
There is no "right" to get married. Both churches and states have reserved the right to restrict who can marry whom. Professions of love are not sufficient to overcome these, nor is procreation.
Gays have exactly the same right to get married that everyone else does. They just have to marry someone of the opposite sex. That they might love someone else is beside the point.
Being gay is not like being a racial minority. Gays are not required to identify themselves as such legally - it's not on their driver's license, passport or any other common legal document. Gays often cannot be recognized as such. Gays can claim to be straight and vice versa and no one can prove otherwise. In short, being gay is not an immutable state, but a choice. As such it's unworthy of being classed with handicaps, race and sex wrt Federal or state protections.
The various differential statuses and rights written into our marriage laws were designed for marriages consisting of a man and a woman. These are not necessarily appropriate for same-sex pairings. Whether it is appropriate to extend these to same-sex marriages should be addressed on an issue-by-issue basis by legislators in advance, and with input from interested parties like insurors. These issues will be addressed, and it will be far more expensive and less orderly if done in the courts after the fact.
The body of law that addresses marriage is large and complex. It would require substantial revision to accomodate new issues that arise with male-male or female-female relationships, and many issues that arise with male-female relationships would not apply. It makes no sense to encumber marriage law with innumerable new "if's" when it is already so complicated.
Such revisions would have to take place in all 50 states. That's a substantial effort. And for what? So a tiny sliver of our population might save some legal paperwork and expense. IMO such a demand is unreasonable.
Although I oppose federalizing marriage law, I would support a Constitional amendment defining marriage as a man and a woman just to prevent chaos.
I recognize that harmonizing marriage laws across the country would be beneficial, however. Surely we have talented lawyers who can write a code for "civil unions", packaging what is appropriate for such couples into something democratically acceptable nationwide. The final product might even result in better marriage laws. So I ask why gays don't pursue this approach?
I've heard some claim that the 14th Amendment somehow has something to do with this issue. I'm sure its authors would be astonished to hear this - I'm guessing that if someone had said "if you give blacks equal rights you're paving the way for homosexual marriage!" he would have been laughed out of the room if not sedated. Those of you who do think that an amendment written almost a century and a half ago can be interpreted so probably owe a huge apology to Senator Rick Santorum.
I guess that's enough flame-bait for one day.