Partisan lines that once fell along regional borders can increasingly be found at the county level. What does that mean for the future of the United States?
Starting before the Civil War era, America's political dividing lines were drawn along state and regional borders. Cities and the then-extensive rural areas shared a worldview North and South of the Mason-Dixon line. While there was always tension within states, they were bound by a common politics. The city of Charleston, for example, was as rabidly anti-North as some inland plantation areas. Economic engines, ways of life, and moral philosophies changed at the 36th parallel, where the North began.
Today, that divide has vanished. The new political divide is a stark division between cities and what remains of the countryside. Not just some cities and some rural areas, either -- virtually every major city (100,000-plus population) in the United States of America has a different outlook from the less populous areas that are closest to it. The difference is no longer about where people live, it's about how people live: in spread-out, open, low-density privacy -- or amid rough-and-tumble, in-your-face population density and diverse communities that enforce a lower-common denominator of tolerance among inhabitants.
The voting data suggest that people don't make cities liberal -- cities make people liberal. Here, courtesy of Princeton's Robert Vanderbai, is an electoral map that captures the divisions:
The only major cities that voted Republican in the 2012 presidential election were Phoenix, Oklahoma City, Fort Worth, and Salt Lake City. With its dominant Mormon population, Mitt Romney was a lock in the Utah capital; Phoenix nearly voted for Obama. After that, the largest urban centers to tilt Republican included Wichita, Lincoln, Neb., and Boise.
The gap is so stark that some of America's bluest cities are located in its reddest states. Every one of Texas' major cities -- Austin, Dallas, Houston, and San Antonio -- voted Democratic in 2012, the second consecutive presidential election in which they've done so. Other red-state cities that tipped blue include Atlanta, Indianapolis, New Orleans, Birmingham, Tucson, Little Rock, and Charleston, S.C. -- ironically, the site of the first battle of the Civil War. In states like Nevada, the only blue districts are often also the only cities, like Reno and Las Vegas.
Because winning a state's electoral votes requires only a simple majority, a single city can change the entire game. Blue cities in swing states that ended up going for Obama last Tuesday include Las Vegas, Philadelphia, Pittsburgh, Denver, the cities of Florida, and the cities of Ohio.
Though not generally considered a swing state, Michigan (with 16 electoral votes) was virtually carried by the Detroit metropolitan area, spread across three counties, and a scrap of Flint. Almost the entire rest of the state went different shades of red.
This divide between blue city and red countryside has been growing for some time. Since 1984, more and more of America's major cities have voted blue each year, culminating in 2012, when 27 out of the nation's 30 most populous cities voted Democratic. According to Dave Leip's Atlas of U.S. Presidential Elections and The New York Times, the 2012 election marked the fourth time in the last five federal election cycles that voters shifted away from the party of the sitting president. Despite that constant churn, one part of the electoral map has become a crystal clear constant. Cities, year by year, have become drenched in more blue. Everywhere else is that much more red.
Comparing the state-by-state electoral maps between the election of George W. Bush in 2000 and Obama's reelection, there are considerable differences. But if you look instead at the county-by-county map, the picture changes. The same poles -- the coastal megalopolises, industrial Midwest, and Mississippi River and New South cities -- have fortified the base of Democratic support for 20 years. Republicans have consolidated themselves in the Mountain West, prairie heartland, and Bible Belt.
Between 2000 and 2004 the maps barely seem to change at all. Some counties, for instance, remain the only blue counties in the entire state, year after year. Even comparing 2004 and 2008, many of the most dramatic differences are simply in the margin of victory in various districts. Mushrooming Democratic popularity during the Clinton years and in 2008, while impressive, largely lights up along the periphery of the current Democratic spine.