The declining popularity of the Modern Library among intellectuals after the Second World War was paralleled by the unprecedented commercial success of the series in the 1940s and 1950s. Never before had the Modern Library sold so many books, in a context of heightened competition with the paperback series. Between 1940 and 1948, sales of regular Modern Library titles increasing fivefold, from $171,346 to $882,809. This commercial success exacerbated the anger of critics, who increasingly saw the Modern Library as a mass-market publishing enterprise threatening real culture.

The Ezra Pound affair exemplifies Bennett Cerf's lack of insight on the new intellectual climate. In 1945, Cerf refused to include poems by Ezra Pound in the forthcoming Anthology of Famous English and American Poetry edited by Conrad Aiken and William Rose Bené t. It was not the first time that Aiken had chosen poems by Pound for an anthology – in 1929, Random House published his Comprehensive Anthology of American Poetry in the Modern Library with poems by Pound. But things became more complicated after the war. For Bennett Cerf and for the editor Saxe Commins, who were both Jewish, Pound was an anti-Semitic traitor who deserved to be punished, not published. The purged anthology was released as a Modern Library Giant in December 1945, and the same month, Pound was incarcerated in St Elizabeths Hospital for the insane.