I think there is much more at play here, but he does have a point.

https://hotair.com/archives/2018/10/15/bill-maher-lets-face-democrats-losing-political-correctness/

This backs up his claim:

https://www.theatlantic.com/ideas/archive/2018/10/large-majorities-dislike-political-correctness/572581/

80% of the American population believes PC-culture is a problem. That is heartening and a problem for the American left. The rot that is social media and traditional media has given leftist crazies a much bigger bullhorn than they deserve.