I'm a cop supporter too - I didn't teach my kid that the police are bad. I think a little extra understanding is in order, even if one acts abusive for no rational reason. I know I sure wouldn't want that job.
I do have concerns when incidents escalate for no reason and somone gets hurt, and like any good American I want to believe that all police are just, good, and not bullies or worse. Like any rational American, I know that all are not just and good. When dealing with police, it is smart to be polite and non-confrontational, and remember that they can kick your ass for fun and claim they "felt threatened." 99.9% won't, but why play the odds?