Election maps show ‘middle ground’ communities are disappearing

This week, the Democratic Party in South Dakota announced it was closing its last two offices in the state. The move surprised some analysts and brought criticism from some quarters as an example of Democrats abandoning difficult political terrain.

But a look at the numbers over the past 20 years shows some of the thinking behind those moves. The changes in culture and politics in that time have left an election map that is full of communities that are either deep red or deep blue, with little room for the political space between. CONT.

Dante Chinni, NBC News