How do you get that he dislikes all of the police. Cops are like every one else. Most are good at what they do. Some are idiots. Kasich just calls it as he sees it.
Cops are like teachers in some ways.
There have been quite a number of pedophile teachers identified recently, and there have been quite a number of bad cops identified recently as well.
Maybe it's the uniform with police, but people don't chastise or attack random teachers because some of the others are pedophiles. If it's police the response seems to be "police are bad", if it's teachers the response seems to be "he/she is sick and needs help". (or .... daaayyuuum, where were these teachers when I was in school, she's kinda hot)