Chad Griffin is president of the nation’s largest gay advocacy organization, the Human Rights Campaign.

David M. Horowitz is national president of Parents, Families and Friends of Lesbians and Gays. Regional directors are listed here.

Sharon J. Lettman-Hicks is executive director of the The National Black Justice Coalition of black lesbian, gay, bisexual and transgendered leaders who support same-sex marriage.

Mel White is founder and director of SoulForce, an interfaith group committed to “ending spiritual violence perpetuated by religious policies and teachings against gay, lesbian, bisexual and transgender people.”

E.J. Graff is the author of What is Marriage For?: The Strange Social History of Our Most Intimate Institution (Beacon Press, 2000) and an advocate for same-sex marriage.

Evan Wolfson is a lawyer and executive director of Freedom to Marry. He argued the Boy Scout case before the Supreme Court, as well as the Hawaii marriage case.

Charles A. Cesaretti is executive director of the Center for Sexuality and Religion, which helps faith communities sexual spiritual health and justice. It is based in Wayne, Pa.

Lou Sheldon is chairman of the Traditional Values Coalition, a conservative group that wants a constitutional amendment that would ban same-sex marriage, ban same-sex unions and ban gays from receiving benefits of any such unions.

Salim Yaqub is an associate professor of history at the University of California, Santa Barbara. He specializes in U.S. foreign relations and is a fellow at the Woodrow Wilson International Center for Scholars, where he wrote about the relationship between Americans and Arabs in the 1970s.