According to the American educator Herbert Kohl, writing about debates in New York in the late 1940s and early 1950s, "[t]he term 'politically correct' was used disparagingly to refer to someone whose loyalty to the CP line overrode compassion and led to bad politics.
It was used by Socialists against Communists, and was meant to separate out Socialists who believed in equalitarian moral ideas from dogmatic Communists who would advocate and defend party positions regardless of their moral substance."