Two articles (the one in the Atlantic has a link to a more extensive background piece) on why this is nuts are worth reading, if you don't already see the problem.
The real problem is not mentioned in either of the articles, though both are fine as far as they go. Today, there is so much commerce that there is not nearly enough gold to support it. This has been a problem even in the past when economic life was much more restricted.
But in a world of 8 billion people, most of whom get most of their income from commerce and not personal production, there just isn't enough gold to give each one a doubloon.
UPDATE: I see Krugman has joined in.
The interesting question is what will happen to monetary policy if a Republican wins next year’s election. As best as I can tell, most economists believe that it’s all talk, that once in the White House someone like Mr. Rubio or even Mr. Cruz would return to Bush-style monetary pragmatism. Financial markets seem to believe the same. At any rate, there’s no sign in current asset prices that investors see a significant chance of the catastrophe that would follow a return to gold.But I wouldn’t be so sure. True, a new president who looked at the evidence and listened to the experts wouldn’t go down that path. But evidence and expertise have a well-known liberal bias.