Advocates for same-sex marriage got a powerful new friend on Thursday: President Barack Obama. In a legal brief submitted to the U.S. Supreme Court, the Obama Administration argues against California's Proposition 8. (For full text, scroll to the bottom of this post) The brief argues that the measure passed by voters in 2008 discriminates against gays and lesbians without justification. The law is not necessary to protect procreation, as its defenders assert, the brief says. "Proposition 8’s denial of marriage to same-sex couples, particularly where California at the same time grants same-sex partners all the substantive rights of marriage, violates equal protection."