Republican Nebraska state Sen. Steve Halloran is facing calls to resign after he inserted a colleague’s name into a passage he read during a floor debate from a book’s rape scene that included graphic detail. Halloran apologized on the Senate floor Tuesday morning, defending his decision to read the passage but saying it was a “mistake” to reference his colleagues.”I apologize for interjecting the senators’ names in the middle of reading a transcription, transcribed testimony in a public hearing, in reference to a book that is in some schools, and in some schools, required reading,” he…