A quick google search gives two quite different definitions of racism:
The first is "prejudice, discrimination, or antagonism by an individual, community, or institution against a person or people on the basis of their membership of a particular racial or ethnic group, typically one that is a minority or marginalized."
The second is "the belief that different races possess distinct characteristics, abilities, or qualities, especially so as to distinguish them as inferior or superior to one another."
I have to say of all the racist people I have met, the first definition has been clearly the issue - i.e the effect of those people on their immediate surroundings, for example a minority group in a community.
I can't say I have ever known anyone racist to the second definition, which is hatred of a group on the belief they are genetically inferior.
Maybe the first one is more likely to be prevalent in working class communities, and the second one more likely to be prevalent in upper class or institutional communities?