Richard Hofstadter (1916–70), in his 1964 essay ‘The Paranoid Style in American Politics’, traces the recurrent fear of conspiracy which dominated the thinking of certain minority political groups in the United States from the Anti-Masonic movement of the 1820s and 1830s to the Black Muslims and White Citizens of the 1960s. That fear has recurred in forms as disparate as Nativism and Anti-Catholicism, certain elements of the Anti-Slavery Movement, Anti-Mormonism, the Manicheanism of particular Greenback and Populist writers, and anxieties regarding a munitions makers’ conspiracy during World War I. The early 1950s, the period in which Pickup on South Street (Samuel Fuller, 1953) appeared, provided two significant examples of this recurrent American impulse: the hysterical Anti-communism associated with the name of Senator Joseph McCarthy (1908–57), and the (possibly more reasonable) allegations, associated with the name of Senator Estes Kefauver (1903–63), of the existence of a nationwide, Mafia-controlled crime cartel. Both of these fears of the period relate, in different ways, to Samuel Fuller (1912–97) and Pickup.

In Dwight Taylor (1903–86)'s original story for Fuller's film, the plot revolves round drug trafficking. The politicisation of that original story material comes with Fuller's adaptation of it, in which the revised plot involves microfilm which communists are trying to smuggle out of the United States. Contemporary British reviewers, ignorant of Fuller's wider work, saw this as the only level of politicisation within Pickup and dismissed the film as a McCarthyite tract. And yet, Pickup is, politically speaking, perfectly consistent with what we know of Fuller both as artist and man. On one level, the political impetus Fuller gave to Pickup's plot is consistent with his romantic nationalism which, in the climate of the early fifties, could scarcely fail to view communists as the enemies of America. On another level, the politicisation seeps some way into the fabric of the film so that, as in earlier Fuller films such as The Steel Helmet (1951) and Fixed Bayonets! (1951), America is seen once more defended by outcasts from American society. In Pickup's case, that defence is provided by the petty criminals of the New York underworld, and the most virulent attacks on communism come from Moe (Thelma Ritter) and Candy (Jean Peters), characters who are no more capable of understanding the ideological debate between communism and capitalism than are Fuller's mercenary soldiers in his earlier war movies.