Herbert was one of President Richard Nixon's economic advisers in the 1970s and in 1976, he came up with the concept of supply-side policies. He was a neo-classical economist, who believed in freeing up the markets, reducing regulation, reducing taxes and less government intervention. There is no surprise that Nixon was a Republican, similar to our (right wing) Conservative party.
http://en.wikipedia.org/wiki/Herbert_Stein
http://en.wikipedia.org/wiki/Supply-side_economics