The 40% who say they don't think he's racist are the 40% who like him because he's racist.
Let's face it, he can say what the hell he likes about Nigerians without losing a single vote. Yes, he's a racist twat, but far too many other people are as well, especially against a group that gets bad press but no fucker really knows anything about.
He doesn't have to defend his position, albeit an old one, because he knows no fucker that's going to vote for him gives a toss.
Sad, but true.