Yet there is an issue with the scale, which is quite distorted by single player/low population (<50k) county values. They should be filtered out for the definition of the coloring scale. They don't provide any good information since county population sizes vary by magnitudes. (I wouldn't even recommending filling the county with a color in these cases as simple dot at the county centroid should suffice)
Granularity matters, counties are a not a optimal unit for this, aggregating by congressional districts would better, yet still not optimal.
[added] Alternatively counties could be clustered to some minimum size. The US Census Bureau provides sets of counties with above 50000 total population as a XLS spreadsheet. http://www.census.gov/people/eeotabulation/data/eeoupcoming....