As world trade imbalances reawaken fears of protectionism, Douglas Irwin reminds us that there was a time when protectionist was a compliment not an insult. Prior to the Great Depression Republican Senator Smoot extolled high trade barriers as “a fundamental and essential principle of . . . economic life.” Ironically Smoot’s handiwork, the 1930 Smoot-Hawley tariff, has since become a cultural symbol for the superiority of free trade...