Affirmative action is a harmful and ineffective policy, but if you speak out against it, you are racist. I'm not here to argue whether you agree with that or not, just using it as an example of something you simply can't criticize without offending innocent people.
More to the task at hand though- I question if he's even really punching down anymore(or even if this is possible- societal status shouldn't shield you from criticism, and there is a difference between critique and baseless insults).
Anecdotally, one of my friends was interviewing a candidate- and the other person conducting the interview asked a thinly veiled political question. The candidate was rejected because of their stance, or lack thereof on this question. This was acknowledged internally, and embraced, and several meetings ensued until HR got involved and had to tell engineers that no- they couldn't discriminate on the basis of political beliefs. And that being sneaky about it by bringing up controversial tech figures in the community and gauging reactions was not actually legal.
