Look at phobias also classic and operand conditioni my and how that might impact on phobias held around specific religious beliefs. Look at post traumatic stress disorder and how being a victim of a racially motivated attack might colour an individual's religious beliefs or views causing racist attitudes to permiate.
I would look into Social Identity Theory (SIT; Tajfel, 1978, 1981; Tajfel & Turner, 1979, 1986) for a theoretical account regarding the relevance of in-group favoritism for forming social identities, and this can be connected to racist attitudes.
One of the best theories I've read is the Social Dominance Theory by Sidanius & Pratto. It is about how all forms of group oppression (racism, sexism, ethnicism,...) are an expression of the human predisposition to form hierarchies. There are several social processes involved in both the genesis and development of Social Dominance and longitudinal research has shown it to be the cause of several racial attitudes.