They cannot.
The republican party is complicit, and supports the evil he does, and more than that, he commands their supporters, so it would be political suicide for them.
Why can’t the democrats? The republicans control all 4 parts of government and even if they had control over the senate, they would need 60% of the votes, a number that is unprecedented in recent times.
The most important thing is to first have a governing body that governs the police, without being police.
Without this, nothing here matters because they haze, and brutalize those who do not conform to their awful internal group standards.
You can literally see what happens to good cops. They get forced out.
The problem with your post, is that you can’t help someone who does not want to be helped.
Ideally that type of person would be kicked out of the force, but instead they comprise of the majority of these forces.
Just to be clear, many if not most agencies have mandatory psych evals, visits etc after different types of incidents, but as you can see, they just don’t solve the problem.