Here’s a legal argument against the same-sex marriage ban which I either heard or came up with a long time ago, but can’t remember which or where:
If a man wants to marry me, he can. If woman wants to marry me, she can’t. That woman is being discriminated against because she’s a woman. That is, by definition, gender discrimination. Gender discrimination is clearly illegal in every state in this country.
I am expecting (hoping!) that the legal team which will tackle the ban on same-gender marriage will use the gender discrimination angle, and I’m also expecting that some people are not going to like it. Purists in the queer movement look like they prefer that we argue the whole thing based on arguing the equivalency of the civil rights of gay, lesbian, bisexual, & transgendered people. However, that is a tricky case to make nationwide regarding marriage when some far more basic rights are denied to queers all over — in 30 states, sexual orientation is not a protected class in employment, housing, etc.
It does seem strange that it may be easier legally to fight bans on same-sex marriage than it is to get individual queer rights. But I also think there is a huge amount of power in allowing the world to see that married couples of all gender combinations are the same. So the first step would be to strike down any ban using all legal arguments available, then let time get us to the point that these weddings are just as uneventful as interracial weddings are today (which I would guess was maybe 10-15 years after it was legally allowed in each area).
I hope it doesn’t take that long — but then slow change is what actually sticks.