Well let me play devil's advocate and tell you why heterosexual marriage should have been protected and preserved as well as encouraged by the federal government in order to fulfill its constitutional obligation to promote the general welfare:
I will say it as IMO to avoid having to dig up numerous links and resources--most of which I have posted in other threads here over the years--that traditional (one man, one woman) marriage was recognized and encouraged by the federal government because:
- Study after study has shown a loving mother and father in the home is the very best circumstance for children growing up in that home. While there will always be exceptions, the children, whether straight or gay, are far less likely to have confusion about their own gender roles, are far less likely to experiment with harmful substances or engage in illegal activities, are more likely to form stable and healthy relationships themselves, and are far more likely to be socially and materially successful when they grow up in a traditional home. All traditional marriage laws in all 50 states were designed to be beneficial to any children born within the marriage.
- Study after study has shown that neighborhoods composed of mostly traditional families tend to be more prosperous and more stable, produce more voluntary social services, are more aesthetically pleasing, produce good neighbors, better schools, and provide a more secure and safe environment to bring up kids.
--Traditional marriage throughout the ages has always been the means of establishing bloodlines and how people are related and in more modern times has been invaluable in studying genetics, dna, and how various issues are transmitted from generation to generation. It has helped people keep track of who their relatives are and prevented the unwanted consequences of inadvertent incest or marrying somebody too closely related.
While single parents and gay parents can do exemplary jobs bringing up children, and I know of many examples in which they do, they cannot provide the same dynamics that a loving mom and dad in the home can do. And strong family ties with the child's natural family are rarely maintained.
And while I have long personally fought for gay people to have the necessary protections and benefits in our common society together, it is for the listed reasons and others that I have opposed changing the definition of marriage to something it never was before and was not intended to be.
I believe that the changed definition strongly signals to the young that marriage is pretty meaningless after all and is not a necessary or even a desirable goal. I cannot see how that will be a good or healthy thing for us as a society.