(no subject)

Can anyone offer a compelling argument as to why same-sex marriage should be legal everywhere in the US? Specifically, why that would be superior, in the long run, to "marriage" being removed as a legal term for everyone, and replaced by civil unions for any two un-unioned consenting adults (of whatever sex/gender)? Because I definitely prefer the latter, but I'm not sure if there are good reasons I haven't thought of as to why same-sex marriage is actually better.

(Leaving aside the question of multiple partners for now, since it raises a different set of issues...)