ethnicist
/ˈɛθnɪsɪst/noun
1An expert in or student of ethnology or ethnicity. rare.
2A supporter or champion of a particular ethnic group or of certain ethnic types; an advocate of ethnic self-determination or nationalism, or of ethnic separation.
3A person with an interest in or enthusiasm for foreign or exotic culture, food, dress, etc.
Origin
Mid 19th century; earliest use found in The Times. From ethnic + -ist.