This I agree with:
"More specifically, Trump won because he convinced a great number of Americans that he would
destroy political correctness."
That was a big part of his appeal. Not just political correctness, but he would stick it to those his base didn't like.
The problem is the next part where the author asserts that political correctness is a big problem and has gotten way out of hand. There are examples of people taking PC a bit too far. There are examples of irrational people on the left. But these are not major issues. It has been blown way out of proportion by people like this author and conservatives in general. It's like voter fraud. Sure, it happens, but it's not nearly as prevalent as it's made out to be, and it's certainly not something to be overly concerned with.
It's OK to point out when people take PC too far in certain situations. It just should be remembered that those are fairly isolated cases, and not part of some huge trend that's ruining America.
Also, while I think this aspect did help Trump, I don't think it's the reason he won. I think the biggest reason he won was the right's 20-year-long campaign against Hillary. They took every chance they had for roughly 20 years to attack her and try to discredit her. It worked wonders. People like my co-worker are the reason Trump won. He bought that campaign hook, line and sinker. He fully agrees Trump is a terrible president, but it's the old "But Hillary". He didn't vote in the election at all.
I think this backlash against perceived PC is part of the reason Trump's base is so fervent in their support of him. I even think it helped push a few people here and there over the fence to his side during the election. But it's a reaction to a problem that almost doesn't exist, and it's not one of the main reasons he won.