“A global power structure that is responsible for the economic decisions that have robbed our working class, stripped our country of its wealth and put that money into the pockets of a handful of large corporations and political entities,” was the wording of a Trump TV commercial late in the presidential campaign, complete with the face of the chief executive of Goldman Sachs, Lloyd Blankfein, on the screen.Yet President-elect Donald Trump has named Blankfein’s friend and associate, the chief operating officer of Goldman Sachs, Gary Cohn, to lead the National Economic Council (NEC), the third Goldman executive tapped for either...