One "Paulist" proposal is that citizens be able to pay their federal taxes in gold bullion at the spot price. This is merely a return to the 19th century practice where tarriffs were actually required to be paid in gold. This leaves the present fiat system in place, but sets up a separate gold standard for anyone who wants to use it.
One advantage for tax-payers is the ability to inflation-index future taxes by buying gold before-hand. For the gummit, an advantage is getting paid in a non-depreciating currency. Why would they want depreciating dollars in preference it gold anyway? Similarly, this will increase US gold stores and thus increase confidence in the dollar.