I like the proposal, but I worry about a cartel obtaining permission from the Commodities and Futures Trading Commission crowding out all other possible competitors who lack the public choice clout (read, me).
Justin Wolfers has the report:
The North American Derivatives Exchange has proposed to run political prediction markets in the U.S. which would be regulated by the Commodities and Futures Trading Commission. But first, they have to convince the commission that these markets serve a useful purpose. Eric Zitzewitz has put together a short comment letter which makes the case: