As the arguments for heterosexual marriage inequality were used to fight same-sex marriage, so the success of same-sex marriage is a living refutation of the argument that marriage requires congenital natural inequality with women on the bottom. Even the campaign for same-sex marriage, consisting of a torrent of moving stories about the happy same-sex couples who want to get married, is a feminist windfall. Maybe marital equality and happiness aren't so incompatible after all.

The very fact that two women can marry alters the perspective of women in a heterosexual marriage. Marriage equality is an advance for feminism too.