… is from William Graham Sumner’s Preface to his 1885 book, Protectionism: the -ism Which Teaches that Waste Makes Wealth:
Protectionism seems to me to deserve only contempt and scorn, satire and ridicule. It is such an arrant piece of economic quackery, and it masquerades under such an affectation of learning and philosophy, that it ought to be treated as other quackeries are treated.