I believe that this leadership gives Unitarian Universalist ministers and congregations some moral and social authority on the question of love and marriage. In some ways, we have more authority on this question than any other question. That authority is the result of our ability to see into the essence of the question of equal marriage rights and see what was most important and true: that the desire of gay men and lesbians to form permanent, faithful, lifelong bonds was as worthy and commendable as the same desires among heterosexuals, and that it was a simple matter of fairness to extend ALL of the SAME rights to gays and lesbians. We were not alone, of course, among religious leaders to see this, and we did not move in exact unison, but no other denomination was so committed, so early and with as close to unanimity.
We need to be aware of our authority on marriage as we approach the question of multi-partnered marriages. It matters to other people what we think.
Having gained some authority on love and marriage, it is inevitable that we will be the objects of other people who want to use our authority to advance their own purposes. If we accede to the passive-aggressive demands of the polyamorists, we will have given away whatever authority we have gained -- we will have been shown to more concerned about avoiding a certain kind of criticism than in thinking through the issue for ourselves.