This piece on recent geographic trends in voting looks at factors such as increases in the prominence of Democrats in urban areas, in homogeneous community sorting, and in single-party voting across a range of issues. The author cites Ron Lesthaeghe and Lisa Neidert’s [work on the Second Demographic Transition](http://onlinelibrary.wiley.com/doi/10.1111/j.1728-4457.2009.00284.x/pdf) in providing a cultural backdrop for these trends.