[Dog Gone]

The language you quoted is a limitation on the states. It also provides that the states may not coin money.

So Federal rules are going to prevail. You could pay in $20 gold pieces, which are still legal tender, but you'd be crazy to do so.

[cleoning]

Ok, the language is limited to the states. But the Founders had no intention of private citizens making payments directly to the Federal Government for anything, so I am thinking their intention would apply to private citizens nowadays (I know no judge would see it this way today).

But still my question is, can I pay my debts in (raw) gold if I wanted to today?