Photo by Steve Snodgrass.

Walkin’ in politically conservative cities, walkin’ in politically conservative cities, nobody walks in politically conservative citiiiiies. Okay this is not very catchy, but Will Oremus at Slate has noticed that it’s true. The most walkable cities are reliably politically liberal — the 19 most walkable are all in states that voted for Obama in 2008, and even the largest conservative cities didn’t crack the top 20.

It appears that density is the key, rather than population — sprawly cities are less walkable, and conservative cities are sprawly. Oremus has a few theories about why density and progressivism go hand in hand:

I see four possible categories of explanations. 1) Liberals build denser, more walkable cities (e.g., Portlanders supporting public transit and policies that limit sprawl). 2) Liberals are drawn to cities that are already dense and walkable (think college grads migrating to Minneapolis rather than San Antonio, or young families settling down in Lowell, Mass., with a walk score of 64.1, rather than Fort Wayne, Ind., with a walk score of 39. 3) Walkable cities make people more liberal (by forcing them to get along with diverse neighbors and to rely on highly visible city services such as parks and subways). 4) The same factors that make cities dense and walkable also make them liberal.

So in short: liberals cause walkability, walkability causes liberals, or something else causes both. Oremus guesses it’s the last one — coastally located cities, he theorizes, are both denser and more open-minded.

What he doesn’t consider, though, is that the causality might run the other way. What if, rather than walkability causing liberalism or vice versa, car-dependency actually causes conservativism? Think about it: all that brain-poisoning pollution, all that sedentary time spent in traffic getting angrier and angrier, all that sick codependency with your oversized SUV. Wouldn’t that turn anyone into a reactionary oil addict?