the issue here reminds me of something the late playwright samuel beckett once postulated regading human relations. he said that all relationships possess a certain degree of a master/slave quality to them and that this is often manifested in our language. in the case of rappers spewing misogynistic comments i believe beckett would suggest that this is a case of male/female conscious and subconscious struggles being amplified through speech. i would imagine that many rappers may have grown up in an environment where disrepect towards women was allowed, either verbally or physically. (and really, how often on this site are women regarded in physical terms?) the language or rap often represents the master/slave quality of certain male positions regarding women. (let's not let heavy metal off the hook here as it can be quite disrespectful to women as well).
in the case of imus, i believe that an incident in which a white male (and let us not think that the white male has now become the most suffered individual in america) uses language that is directed towards individuals that have enjoyed assimilation into higher education and a certain level of empowerment, then the individual making that comment may become an allegory for the master/slave dynamic that has existed throughout american history. the reference to these women with language that can be associated to times of slavery or even more recent times where violent prejudices still occupied the streets will bring up connotations of racism. this does not define imus as a racist but it does define his language as racist. the rapper guilty of employing the same vernacular is using language that is misogynistic and also a part of the master/slave relation only as it is applied to gender relations as opposed to race. either way, these are clearly examples of language being used in such a way that it creates a discourse guilty of demeaning thought.