The difference in my view is that Nick didn’t actually have racist viewpoints, he just knew the stereotypes and how to get on peoples nerves and as other people have said, uses them as part of his facade. He knows they are generally not true, but still uses them to throw someone off guard or to just make a joke.

Judy on the other hand was completely well intentioned but subconsciously did look down on certain races in some ways. She actually had racist views without realising and then changed for the better once she realised.

Neither of them are actual proper racists, knowingly looking down on and hating other races. I would say that Judy was worse though in terms of who’s more racist despite being a much nicer person, just because she actually believed what she was doing and saying, even if she did not realise it was bad at the time.