They do have a habit of doing this. They don't seem to understand that slavery long ended. It's not some secret that it happened either. In fact if you really start to look into the details of that then you're going to start to come up with some difficult problems such as that basically Muslims are actually the blame for the whole thing.

What they're doing with that is like saying we need a truth commission on WW2.

These people turn history into a kind of religion but they don't really study it much either.