People like to say, "Ron Paul's got a great domestic program, it's just his foreign policy I don't like." Really, people only say that because they don't take the time to understand what Ron Paul's domestic program is all about, or at least the more insane details thereof. One particular example of this is Ron Paul's view on monetary policy.
Paul, who likes to present himself as some sort of Constitutional scholar, has said in his last several concession speeches that "the Constitution still says that only gold and silver can be legal tender!" This absolutely absurd reading of the Constitution is universally rejected by anyone who can read English. Let's look at Article 1, Section 10, from which Ron Paul draws his support:
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.
Emphasis mine. However, it is also worth noting that Article 1, Section 10, is conveniently titled "Powers Prohibited of States." Ron Paul might still have at least a non-farcical point if it were not for the existence of Article 1, Section 8 (helpfully titled "Powers of Congress"):
The Congress shall have Power. . . To coin Money, regulate the Value thereof[.]
Get it? The reason states do not have the power to create their own legal tender (other than gold or silver coin) is because that is a power expressly reserved to the Federal government. Remember that this was one of the central evils of the Articles of Confederation - that every state had its own currency, which hindered trade and created economic chaos - and so the founders reserved to the Federal government the right to establish a single currency for the whole nation. States are absolutely and completely prohibited by these sections of the Constitution from generating their own currency other than literal gold and silver coins.
Therefore, even if you ignore that Article 1, Section 10 is expressly confined to restrict the powers of the States, it would not stand for the proposition that Ron Paul wants it to stand for, which is that the Federal government must constitutionally adhere gold/silver standard. It would instead mean that the Federal government was prohibited from using currency that was not literally gold or silver coin. This conclusion is of course absurd (and ultimately would have no salutary effect on monetary policy whatsoever) which is why no person who hasn't suggested that the government is using paper money to try to track you has ever suggested it.
I get that some people want someone who is a principled, small government isolationist constitutionalist. Sadly, Ron Paul is not that person - he's just a nut onto whom people are projecting those qualities.