The words “supply side” are coded as right-wing. They summon memories of the curve that the conservative economist Arthur Laffer jotted on a napkin in the 1970s, showing that when taxes are too high, economies slow and revenues, paradoxically, fall.1 This led, in part, to decades of Republican promises that cutting taxes on the rich would encourage the nation’s dispirited John Galts to work smarter and harder, leading economies to boom and revenues to rise.
