Splitting income makes little difference for opposite-sex married couples but creates tax issues for same-sex partners because of DOMA. Here are just a few of the problems that the IRS has explained in various publications.
But their focus will probably be confined to the question of whether the difference in treatment of same-sex and heterosexual married people as far as federal benefits are concerned is unconstitutional.
Another difference: the campaign for same-sex marriage has benefited greatly from personal testimony by gay couples, speaking out in legislative hearings and campaign videos.
Moreover, the sheer sexiness of "A Little Night Music" (which is, among other things, a musical about the difference between sex and love) comes across with breath-catching directness.