Electoral Map by Partisanship, County, Population Density -- by Chris Howard. Good stuff at the link, including high-res version. Red/blue maps exaggerate geographically-arge but population-light areas. Mapping at county level, 100 votes per dot, this colorization is a clearer portrait of the very mixed US political landscape. Population density is much more clear - try scanning westward from the East Coast, or see the distribution of voters in Florida, shown in a closeup).
Election maps are telling you big lies about small things In 2012, about the same number of votes were cast in these 160 counties as were cast in the rest of the country. But, your run-of-the-mill election map won't show you that. https://www.washingtonpost.com/graphics/politics/2016-election/how-election-maps-lie/