And dictating what is considered legal tender
Discussion
Section 10 Powers Denied States
Clause 1 Proscribed Powers
No State shall enter into any Treaty, Alliance, or Confederation; grant Letters of Marque and Reprisal; coin Money; emit Bills of Credit; make any Thing 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.
!! "make any Thing but gold and silver Coin a Tender in Payment of Debts" !!
They defined legal tender in the first mother F'ing article of the Constitution... we just fail to follow our founding document