Maps based on census data use counties as the dividing lines. This religious belief map is typical.
Counties are ENTIRELY DIFFERENT UNITS west and east of the Dry Line. East of the line, counties are small and about the same size, so they’re practical units for illustrating poverty or religion or voting. You can see relative dominance or patterns of change easily. West of the Dry Line, some counties are HUGE and some are midsize. This leads to wild inconsistencies. Half of Arizona looks like one religion or one party, a significant part of the whole nation even though it contains a few thousand people. A similar sized HUGE county near Los Angeles contains 3 million people. In the east, an area this size would cover a hundred counties in three states.
There must be a more consistent way to show locations without unjustified fudging or heavy computation. Maybe mark each county as a dot on its county seat, then blur the zones between the dots?
