Of all the splits that define the Red/Blue divide in American politics, the most dominant one may be the one that runs through everyday life, where we live. Those environmental differences are a crucial part of what makes the partisan divide so intractable.
The Democratic Party is increasingly tied to urban neighborhoods and urban living. The Republicans, on the other hand, are the nation's rural party. When you look at election results since 2000, that urban/rural divide supersedes even the regional divides that we use to understand the country.
For instance, look at the state of Georgia in the Southeast, and Wisconsin in the Midwest. In many ways they are very different states, from their economies to their racial and ethnic demographics.
But look at the vote out of the most populous counties in those states, Fulton and Milwaukee, and you'll see places that are moving in the same direction - and further away from the rest of their home states.
In 2000, the partisan gap between the way Fulton voted and the way the rest of Georgia voted (every other county besides Fulton) was 33 points. Democrat Al Gore won Fulton by about 18 points and lost the rest of the state by 15 points.
By 2016 the gap between the way Fulton and the rest of Georgia voted had climbed to 51 points. Democrat Hillary Clinton won Fulton by 41 points and lost the rest of the state by 11 points.
In 2000, the partisan gap between the vote in Milwaukee and the rest of Wisconsin (every other county besides Milwaukee) was 24 points. Gore won Milwaukee by about 20 points and lost the rest of the state by 4 points.
By 2016 the gap between the way Milwaukee and the rest of Wisconsin voted had climbed to 44 points. Clinton won Milwaukee by 37 points and lost the rest of the state by 7 points.
Look at those numbers and the regional differences between Georgia and Wisconsin don't seem to matter as much as the urban ties that bind Atlanta and Milwaukee. Both are big cities with diverse populations that are trending much more Democratic than the rest of their home states.
Taken together the numbers suggest a common urban political culture is rising out of the nation's big cities that overrides regional differences. And that culture is about more than just happenstance - it is about people from different political backgrounds desiring different things.
Consider a question from a recent Pew Research Center survey on the kind of community that people prefer to live in.
Among Republicans, 65% said they preferred to live in a community "where the houses are larger and farther apart, but schools, stores, and restaurants are several miles away." Among conservative Republicans, 68% preferred that choice. That's a vision of an ideal community that is more exurban or even rural in its nature.
But among Democrats, 61% said they preferred a community "where the houses are smaller and closer to each other, but schools, stores, and restaurants are within walking distance." Among liberal Democrats, the figure was 69%. That's a statement that is a pretty good proxy for an urban or dense suburban environment.
None of this is meant to reduce the Red/Blue divide into a set of cosmetic, stylistic differences. Rather, the urban/rural divide is evidence of the opposite. It shows how deeply the differences between the two parties run.
The kind of place you live in plays a big role in who your neighbors are, what your work commute is like, the kinds of stores and restaurants near you and, ultimately, how you see the world you live in.
And when you view the partisan divide through that prism, you understand why it is so hard to overcome. It isn't just about people's politics, it's increasingly about their identity and how they live their everyday lives.