you're not understanding that the racist cop/politician is the one controlling the machine, telling the programmer how to design its algorithms, and protecting the system from being audited
Racists or other biases at the top level can, to a limited degree, be dealt with through politics.
You can, at the very least, make biased people want to not seem biased.
However, bias at the lower levels is much harder to deal with. Especially if their superiors don't care beyond impressions.