Testing has been done that shows the response rate for job applications is lower for blacks, all else being equal. This is reflective of all experiences along all of a lifetime for some people, people who know that on mere sight they are thought less. The high level of effort needed to suppress anger in response is enough to lead to measurably higher average stress levels.
Being visibly different is like walking through water, when the mainstream race walks through air. Appearance may seem the same, but everything takes greater effort, and an all-pervasive sense of injustice oppresses at all times. Now add that instead of pride in your past, there is also shame, not because of guilt, but because victims feel shame. This is your identity. Then you find, as all long-term victims do, that some of the narrative of the abuser or dominating party seeps into the psyche. You unconsciously find some biases and rankings, such as by skin tone, creeping in to where they have the least right to take hold. More anger, first at yourself, then at who ultimately caused this, too.
Then there are the encounters with the justice system, starting with the police, then with the bail-fine-late.fee scam run in many places, then with obligatory sentencing. So, you say, I'll be a good American and improve my lot, one way by participating in the system with my voice. Then comes overt voter suppression. Blatant. (SCOTUS practically had to use a spittoon after announcing its decision on N. Carolina, for example.) So, if denied voice, what do you have left as an alternative?...
The US is damn lucky to have such a noble, patient, decent, kind black population, taken as a whole.