There will always be people who believe mad things - human nature, unfortunately.
The most a society can do is damage limitation but IMO that's hugely important.
I'm with those who say that even one instance is one too many. Working out whether this is isolated or is a "tip-of-the-iceberg" thing is useful because is gives you a handle on where the underlying problem is.
Each society has its own weaknesses which can be exploited by the bigoted. Racism in one place can be quite different from racism in another.
I'm interested in a detached way as to what is happening in this town and how this situation arose. At a distance, there's not much else to do - that's for the locals to sort out.
But I am shocked. We have to be shocked. We have to keep in mind, always, what we think things should be like and recognise when they aren't.
Saying, "oh, there's tons of racism in other places" - or on the other hand, "not everywhere is like that" - misses the point. That other places are better or worse doesn't make this one OK.