Christianity NEVER sanctified homosexual unions. To imply that "blood-brother" relationships were sexual in nature is dishonest. The Greeks and the Romans were accepting of homosexuality, but NEVER considered marriage as other than heterosexual. The Native Americans were not part of Western Civilization.
So much for these "scientists".
Right and neither did Jews. What we are seeing is the deconstruction of the Judeo-Christian traditions of 1000's of years in favor of doing what pagan cultures have done. I don't think a lot of it can be stopped. The constitution did not anticpate this onslaught.