I think you've nailed it there Dan
Over 45 white voter mobilisation by Trump (and Farage) is what fired him over the winning line, below this age, he lost heavily. Trump could say what he wanted about Hispanics and Muslims, without it making a jot of difference, even in strong Latino states like Florida. Some of this voter group he engaged are marginalised because over their lifespan it's changed from them being able to speak as they please, without fear of censure, to having to show respect (or at least restraint) to other groups of people. The knock on is it causes some people to wilfully confuse redressing a long standing imbalance, with being oppressed.
The "PC Gone Mad" label is just a snappier title for "Bigots Can No Longer Say What They Want".
You might hear people saying things like, "you can't sing ba ba black sheep any more" or "you get locked up for saying you're English these days" but everyone knows that these are just inventions, not real. What they're really saying is, "I can't call a Mexican a beaneater anymore" and they don't like it.