For some reason I can't fully explain, people who regularly break the law take a very confrontational stance when questioned by the police.
That confrontational stance tends to make police suspicious.
Law-abiding folks tend to take a police stop in their stride.
Of course you have the occasional self-important person who doesn't have time for your police shenanigans. (Damn it! Don't you know who I am? I'm the secretary to the assistant city water commissioner for Lake County! I'll have your badge for this!). Or, my personal favorite, "I pay your salary" (Yes, people actually say that, not just on TV).
Being a former police officer yourself, you opinions matter the most in a conversation like this. Tell us.......did you ever work with officers who had a chip on their shoulders like the Dems claim all the time; cops who simply pulled over people of color just because they could for no reason?
Complicated question ... I have never worked with anyone who would pull someone over just because of their color. That would be such a waste of time and cops don't typically have that much time to waste. If you're even half way busy at your station, you're always a week behind on paperwork. Why add to that?
On the other hand, I work in a large, metropolitan department and anyone with that kind of attitude will be weeded out early in their career. As for smaller, less managed police departments, I can't say what behaviors will and will not be tolerated.
There are close to a million sworn members in the country, nearly 5,000 independent police and sheriff's departments. With any demographic that large, you're going to get your fair share of jerks. Police are, after all, only human.
But, police policy comes from the top and the guys (and gals) at the top know that racist, unprofessional behavior puts any department at risk. So, as in any organization, from McDonalds to NYPD, behaviors that put the company at risk aren't typically tolerated unless the folks at the top let them.
One thing I have learned on the job, race and crime are utterly and completely unrelated. I've arrested jerks, idiots, morons, and cretins from every race. I've yet to arrest a Jewish jerk ... but they have to be out there. I get just as much lip and attitude from lily-white college hipsters as I do from Hispanic gang-bangers, often more. No race has a monopoly on law breaking and you soon learn in this job that you're looking for behaviors, not colors.