I'd say you could read it either way - I mean he could be meaning it straight, or he could be using irony, and could be pointing out that there's a lot in common between a kind of law enforcement ("Somebody didn't get too far yeah") and lynch law. And pointing out how both of them have the same kind of populist saloon bar appeal.

Or he could be laying out those two ways of reading the song, and saying, "You make up your mind".

Incidentally, I can't see where the racism as such comes in the words of the song. They lynched the odd white guy too, I believe. But, as with the legal killings you have these days, it just tended to be black guys disproportionally often