How many counties in the 2016 Presidential Election potentially had zero or close to zero whites who voted for Hillary Clinton?
This question came up while reading about Clarendon County, South Carolina (
https://en.wikipedia.org/wiki/Clarendon_County,_South_Carolina). Hillary Clinton winning 50.2% there almost exactly matches the black share of the population in the 2010 census of 50.1%. Even as recently as 2012, Democrats won enough of the county vote to suggest they had at least high single digit support among whites. Of course, turnout and other factors may be at play here too.