The U.S. Supreme Court’s April hearing and June ruling on same-sex marriage will be historic for the nation’s religions as well as for partisan politics, law, and society. There’s sharp division in this case among faith groups, and sometimes within them, so reporters will want to carefully monitor the inflow of religious and moral arguments as “friend of the court” briefs are filed in coming weeks.

The court defines two issues: Does the Constitution’s “equal protection” clause require that all states issue same-sex marriage licenses? Does the same clause require that a state recognize all marriages lawfully licensed by other states?

An implicit issue: whether judges or state legislatures and voters have power over contested social policies.

Religious proponents of marriage change are confident of Supreme Court victory and likely to file briefs. They include liberal Jews, Unitarian Universalists, and the Metropolitan Community Churches (whose primary ministry is with gays, lesbians, bisexuals and the transgendered), along with organizations of atheists and humanists.  Defending traditional marriage  are the the leaders of the Roman Catholic Church, Eastern Orthodoxy, evangelical and conservative Protestants, some African-American Protestants, the Church of Jesus Christ of Latter-day Saints (“Mormon”), Orthodox Judaism and Islam.

But what about the so-called “Mainline” Protestants who’ve lately been shifting -- especially at the level of pulpits and church boards -- in favor of gay couples?