You should be able to use exclude in this context (though perhaps its noun form exclusion conveys this meaning better).
"Discrimination can be demonstrated through insulting, marginalizing,
or [excluding]/[exclusion of] a race (from something like decision
VERB [WITH OBJECT]
1 Deny (someone) access to a place, group, or privilege.
‘As we saw above, early migrants were largely excluded from access to public housing by complex residence and qualification rules.’
NOUN [mass noun]
1 The process of excluding or the state of being excluded.
‘I wasn't sure whether the issue was one of social privilege or gender
exclusion, or both.’
‘Both sides of this issue reflect the social and geographical
exclusion of black people in a discriminatory society.’