Elizabeth Marquardt outlines the three avenues from which group marriage will come : the fringes of the left, from the darkest corners of the fundamentalist right, and from the laboratories of fertility clinics and hard scientists around the world.

Mainstream cultural leaders have also hinted at or actively campaigned for polyamory. Roger Rubin, former vice-president of the National Council on Family Relations—one of the main organizations for family therapists and scholars in the United States—believes the debate about same-sex marriage has “set the stage for broader discussion over which relationships should be legally recognized.” The Alternatives to Marriage Project, whose leaders are featured by national news organizations in stories on cohabitation and same-sex marriage, includes polyamory among its important “hot topics” for advocacy. The Unitarian Universalists for Polyamorous Awareness hope to make their faith tradition the first to recognize and bless polyamorous relationships. Meanwhile, a July 2009 Newsweek story estimates that there are more than half a million “open polyamorous families” living in America. Nearly every major city in the U.S. has a polyamory social group of some kind.