That's because they are not being dense and refusing to understand two different spellings with two entirely different contexts and connotations. It was still in bad taste, and of course controversial, but he did not call the president a six-letter N-word; he called the president a five-letter term of affectionate respect between two black Americans. As a white guy, I keep my hands and judgment off of it actually.
Willie received flak for it. Didn't back down though as they're different words and the lessor usage had a pointed message about decorum
I know that it was mentioned on both MSNBC and FOX. It may have been mentioned on other networks, but since it isn't a major news story it doesn't warrant more than a brief mention.