Many studies show a link between political orientation and brain structures. To avoid poisoning the well, let’s just call the neurological/political types AGC (anterior cingulate cortex) and AMY (amygdala), depending on which brain structure is relatively large.
Note that these brain differences dictate general emotional and cognitive behavior, not positions on typical policy questions.
I’m guessing that urban dwellers have roughly the same proportion of AGC and AMY types as rural dwellers. I’ll guess that, similarly, ethnic differences and wealth differences do not correlate strongly with this brain-type differentiation. Political alignments which pit haves vs have-nots, or management vs labor, or urban vs farmers, race vs race, North vs South etc. will lead to each of two parties having a mix of the two brain types. (And this might have led to the ability for each side to understand the other: a pro-business party could understand pro-labor viewpoints and vice versa, since each side embraced the full mix of cognition types.)
But, relatively recently, American politics have evolved so that a person’s political alignment is now strongly correlated with brain type!
It might be interesting to consider why this has happened and what the implications are, but — expecting to get booed down just for writing this much :rolleyes: — I’ll leave those questions in the air for now.