Which came first, the city or the liberal?

Citizens in urban areas disproportionately support Democrats, and citizens in exurban areas - the sprawl far away from urban centers - generally support Republicans. Rich or poor, even controlling for race and other factors, the cities are Blue and the exurbs Red. Is this because living in a diverse, dense community forces individuals to value policies that help all citizens, while those in homogeneous areas whose only contact with strangers is through cursing at them in traffic seek to evade responsibility for their fellow human beings? Or is it just that liberals are more likely to enjoy cities for their culture and their activity and choose to live there, and conservatives generally tend to prefer low density living?

In other words, does the urban environment breed progressivism, or simply attract that which already exists?

Outside Washington, DC, the local community and a developer are working together to create high density housing and some office space right next to the Vienna metro stop in suburban Virginia, designed to enable residents and workers to avoid having to commute by car. Given the skyrocketing prices in Eastern urban centers including Washington due to high demand, and the growing problem of traffic in the region, creating more of what people want - walkable, transit-oriented communities - is a clear win.

But the area Congressman opposes the plan, reportedly due to its likelihood to attract Democrats. In the last election the Congressman, Thomas M. Davis III, lost for the first time one nearby precinct, next to the Dunn Loring Metro station, where a similar development now exists. These new condos surely haven’t changed anyone’s political views on their own, but is the Congressman just afraid of attracting some existing Democrats into his district, or is he more concerned that development which facilitates cultural participation at the expense of profligate gas guzzling will erode support for his world view in the long run?

If there is any truth to the thesis that the form of a community influences its members, then in planning for the long run progressives should promote as widely as possible the expansion of our urban cities and the evolution toward a more livable environment of those cities, especially throughout the South and Midwest, which lack a vibrant downtown today.