Sentence:  Abraham Merritt wrote for the pulps and never in his lifetime achieved critical success. Yet he had a devoted following in the science fiction <WSD>ghetto</WSD> who admired the clarity of his style and his power to evoke moods. 
Meaning of the word marked with <WSD> tags:  An isolated, self-contained, segregated subsection, area or field of interest; often of minority or specialist interest.