We've been down that road before, and it didn't work out all that great then.
Prior to Masschusetts allowing same-sex couples to marry, I thought civil unions were a fine idea, too.
We ought to be getting these marriage bigots admitting that they have to strip away rights these Americans already have to do what they want to do.
Why aren't people hammering the marriage bigots with this?
There's a manifest difference in a debate which has as its founding proposition that same-sex marriage is a theoretical construct in the US -- which is the proposition marriage bigots want to promote -- and the debate which has as its founding proposition that same-sex marriages are already here, and there thousands of them.
The latter forces the marriage bigots to come out and admit that their proposed amendment and their goals destroy real marriages between real people -- thousands of marriages between thousands of people.
The "conventional" definition is wrong, since, as noted, same-sex couples can and do get married right here in the US of A. But it does mean they are misinformed as to what marriage means in the US.
And those people who believe that people who are married should stop being married simply because their marriage does not fit a "conventional" definition most definitely are bigots.