Why not pass the amendment and let the state legislatures debate the issue? The amending process itself lets Congress kick the subject down the field and let the states settle it. If its unnecessary, then it will die before it ever becomes a part of the Constitution. I don't see what is anti-federalist about it.
Your post amounts to "why not let the states debate a Federal amendment, then they've had their say - and if 75% of the states decide that your state can't give inheritance rights to domestic partners, too bad - you lose."
I'm going to assume you know enough about "Federalism" to know that this ain't it. Please don't prove me wrong.
As I said, I have no use for brick walls. I'm done. Enjoy your windmills.