I hear what you say.

This "test" should be perfectly routine, as "married is married".

But the very fact of its routineness is another nail in the argument that "marriage can only be between a man and a woman". The state's role in marriage is limited, but this is one of the roles.

And just today, the polls in California are showing weak support for the "rescind gay marriage" ballot question; it's losing now, and should only lose support between now and November.

The more normal same-sex marriages are, the more routine, the less support there is for banning them.