" But progressive as it could be, American populism also lent itself to more reactionary impulses. Suspicious of big capital, it was equally hostile to the big state; and much as it claimed to champion the little man, it often took up cudgels against those seen as the conscript army of unwanted change—immigrants. Who these immigrants were depended on the most recent wave of arrivals. In the 1840s, it was the Irish and thus the Catholics; in the 1850s, the Germans; in the 1890s, the Italians—and therefore the Catholics again. It was also a fairly natural step from anti-big-business populism to protectionism, and almost as natural to progress from there to isolationism. "

― David Aaronovitch , Voodoo Histories: The Role of the Conspiracy Theory in Shaping Modern History