A similar pattern can be found in the distribution of votes in the 2012 US presidential election or in French support for Marine Le Pen’s National Front in the 2015 regional elections. It is very likely to be found in the United States’ upcoming presidential election. Many citizens live in places where a large share of their neighbors vote the same way they do.
This voting geography is indicative of a deep economic, social, and educational divide. Affluent cities, where university graduates concentrate, tend to vote for internationally-minded, often center-left candidates, while lower middle-class and working-class districts tend to vote for trade-adverse candidates, often from the nationalist right. It is no accident that mayors from the center-left govern New York, London, Paris, and Berlin, whereas smaller, struggling cities tend to prefer hard-right politicians.
Regional or local voting patterns are as old as democracy. What is new is a growing correlation of spatial, social, and political polarization that is turning fellow citizens into near-strangers. As Enrico Moretti of the University of California at Berkeley emphasized in his book The New Geography of Jobs, the salience of this new divide is unmistakable: university graduates account for half of the total population in the most affluent US metropolitan areas, but are four times less numerous in worse-off areas.
Economic shocks tend to exacerbate this political divide. Those who happen to live and work in traditional manufacturing districts caught in the turmoil of globalization are multiple losers: their job, their housing wealth, and the fortunes of their children and relatives are all highly correlated.