They are worried about being labeled a racist, because that carries a heavy social cost. They can be very easily fired, lose their jobs only based on vague allegations.

We live in a time where slander carries virtually no penalty and big corporations are terrified of being seen as anti-PC.

The mainstream media and internet outrage mobs can very easily ruin anyones day. It doesn't matter if they are right or not. Sometimes the "news" are entirely fabricated.

There are reasons to avoid being called racist, or not being PC, but anybody can call anybody anything - it's the arguments that matter. Fearing participating in a discussion and maintaining views carries a possibility of being wrong without correction, which should reasonably be avoided.

Unfortunately we don't have ways of reasonable exchange of opinions in our populism times.

Legal system was put in place to prevent mob rule. Internet has again enabled mobs to go around and freely harrass, bully and target individuals in order to enforce their own ideals, instead of what is written in the law.

What makes someone upset is not the same what is unjust.

Who controls what is PC? Now and 10, 20 years from now?

I've only heard of people losing their jobs over specific and strong allegations of aggressive bigotry.

Yes. For example, being anti-illegal immigration and pro strong national borders is something that is hard to talk about without being labelled a racist.

No, it’s not — you just have to avoid saying things which are racist or being dishonest about your motivations. For example, if you want to talk about illegal immigration don’t use rhetoric of the “brown criminal hordes” genre and hope that your audience isn’t aware of the stats. Do be prepared to talk about your proposed legal changes and what problems they address.

Maybe in your social/family circle, but up here in Portland and in my observable social circles, it's a topic that you can't discuss except for with people you know really well. Or rather, you can, and the person on the other side might not call you racist to your face, but they'll entertain no discussion of the topic other than suggestions that you are a bad person for not being compassionate enough. The fact that you have to give a disclaimer along the lines of "Don't get me wrong, I think Trump is an idiot and I have voted Democratic since I could vote..." to even have anyone participate in the conversation, is telling.

I even made a throwaway because I am scared of being viewed as a racist in my workplace.

I haven't seen anyone taking a non racist stance on those issues get called a racist.