The mayors of America have blessed the Marketplace Fairness Act, as Tom Cochran, CEO & executive director of the U.S. Conference of Mayors, writes in Real Clear Politics. This, of course, is the legislation that allows states, cities, towns, villages, and wide spots in the road (about 9,600 jurisdictions in all) to collect taxes on things their citizens buy online and obliges the sellers, no matter where they are, to do the tax collecting.  So if you live in Chicago and buy a guitar from an online seller in Los Angeles, that enterprise is obliged to add whatever Chicago would have collected if the instrument had been sold by an establishment on State Street and then send the money on to Mayor Emanuel to spend according to his city’s needs.