Courtesy of a link at Mr. B’s place, I came across something called ‘The Racial Dot Map‘, from the Demographics Research Group at the University of Virginia. Here’s a scaled-down representation (clickit to biggit). I recommend consulting the original, scalable version to see specific areas in more detail.
It’s very interesting to look at that map, and then compare it to this one, showing the results of the 2016 Presidential election by county.
As Mr. B reminds us, ‘correlation does not imply causation‘ . . . but there’s an awful lot of food for thought in the visible correlation between those maps. Put them on your screen (or, even better, two screens) side-by-side, in full size, and see for yourself.
EDITED TO ADD: As suggested by Mr. B in a comment, if one looks at the US murder map by county, there’s also an interesting visual correlation.