That statement is a bit vague, everyone is going to substitute their own interpretation in. The police don't target racial minorities because they are racist. People who want power over others sign up for policing - and then go after groups who have the least ability to fight back.
The middle income might know the symptoms, but they are missing the cause. The cause is that if a fellow wants to hurl someone else to the ground, kick them and keep them down without a fair fight then their best chance as getting to that situation is to sign on to the police. This is an inescapable structural pressure that needs constant attention.