Partisan Clustering at the Neighborhood Level

Emily Badger, Kevin Quealy, and Josh Katz present an info-graphic-rich data journalism feature that reveals the partisan divides evident in the geography of the United States—in far greater detail than the red-blue and urban-rural divide that is already searingly rendered on so many elections maps. The big surprise of this exercise: the partisan dive of U.S. communities is visible at the local level, within urban areas.

"Democrats and Republicans live apart from each other, down to the neighborhood, to a degree that raises provocative questions about how closely lifestyle preferences have become aligned with politics and how even neighbors may influence one another," according to the article.

The analysis is made possible by analyzing the individual addresses for 180 million registered voters. The data reveals that "nearly all American voters live in communities where they are less likely to encounter people with opposing politics than we’d expect."

Maps of Los Angeles, Chicago, Dallas, and New York top the article, but the same patterns are visible in Atlanta, Baltimore, Austin, Indianapolis, Boston, Cincinnati, Charlotte, Detroit, Birmingham, Columbus, Denver, Houston, and more.

As for what explains these patterns, the article suggest that geographic alignment follows educational realignment,"with the changes concentrated in highly educated suburbs and more working-class towns and rural communities." Racial segregation also plays a factor in partisan clustering, according to the article. "African-American voters in particular are overwhelmingly Democratic and also residentially segregated (metro Milwaukee’s map of partisan segregation, for one, resembles its map of racial segregation)."

A lot more analysis on both cause and effect is included in the source article.