In the United States, racism and casteism frequently occur at the same time, or overlap or figure into the same scenario.
What race and its precursor, racism, do extraordinarily well is to confuse and distract from the underlying structural and more powerful Sith lord of caste.
Like the cast on a broken arm, like the cast in a play, a caste system holds everyone in a fixed place.
It is caste or rather the policing of and adherence to the caste system.
Race and caste are not the cause of and do not account for every poor outcome or unpleasant encounter.