"opponents of "political correctness" who advocate for the freedom to express now-unpopular racist and sexist viewpoints."

You had me until this. What I don't like about PC isn't when actual racist comments get shouted down or whatever, which is what your comment implied. It's when non-racist statements are misconstrued as being racist in order to silence political opposition. For example when opposition to affirmative action is enough for some activists to try to get someone fired.