[DBrow]

“clearly defined in the Constitution, should be a no-brainer for the court.”

Yet we have paper money, and the court decided that it was OK in 1871 or so, and they did it without the help of emanations and penumbras. “Coin” became “print” and “paper” by stroke of Supreme pen.

“To coin money, regulate the value thereof, and of foreign coin, and fix the standard of weights and measures; “

“Section 10. No state shall enter into any treaty, alliance, or confederation; grant letters of marque and reprisal; coin money; emit bills of credit; make anything but gold and silver coin a tender in payment of debts; pass any bill of attainder, ex post facto law, or law impairing the obligation of contracts, or grant any title of nobility. “

[2harddrive]

Great quote! But, did “Federal” paper money exist in the US at the time of the revolution? Or maybe they just had private bank notes, or State currencies? When or how, was paper money legalized for the fed.gov, without an Amendment? Or maybe it was ALWAYS legal for the Fed.gov, and it was STATES that were limited to gold and silver coin? What is your thinking on this? Yes, the States have rules on what constitutes legal tender, but does not the Fed.gov also?

[ROLF of the HILL COUNTRY]

While you quote the Constitution correctly (accept for punctuation), you err in combining the two sections.
The first, from section 8 of Article I, states a power of Congress. The second, is from section 10, which addressing restrictions on the member STATES, not the Federal Government.
To my knowledge, there has never been a de jure restriction on the Congress from issuing paper currency; they did so during the revolution, and from 1791 up to 1832, when Jackson abolished the United States'Bank.