Racism is like a disease.
It can be carried unbeknownst to the carriers, many thinking that they are immune simply because of who they think they are. Like a disease, it can be present without open symptoms until there is a sniffle or a light headed or slight loss of balanced reasoning. It can come on in a virulent fashion and manifest in hate speech, rudeness or paranoia and fear.
Using the disease model might be one way of capturing it and putting under close scrutiny for all the signs tha