I don't disagree with your premise, but if something like half the country doesn't agree that the cops are fundamentally flawed, labeling them effectively as an extremist group will only further entrench their stance that "you're crazy, we're right."

Edit: for example, I think that your other post with the five bullet points could hold up to reasonable scrutiny when presented to the pro-cop crowd, but would likely fall on deaf ears with them if you lead off with the paramilitary framing.