Every area of study has its classic puzzles; the “anomalies theorists” pay their dues by proposing explanations. For the biology of sexual selection, it might be the peacock’s tail. For early-20th-century physicists, it was the black body radiation problem. For comparative political sociology, it is, in German historical economist Werner Sombart’s phrase, “Why Is There No Socialism in the United States?” For over a century, the absence of a mass socialist or labour party has been a defining aspect of “American exceptionalism.” But what if that were no longer true? What if socialism were to become a major force in American politics, even as it declined in Europe?Subscribe or Log In to read more.