How will they vote in 2016?

Philip Bump writes in the Washington Post about the Democrats' white voter problem. First, he shows us this presidential preference map:

Bump writes,

While there were 2,126 counties that voted Republican all four elections and only 461 that consistently voted Democratic, significantly more people live in those fewer -- and more populous -- Democratic counties. So there is a base of 132 million people (using 2014 population estimates for counties) that have backed Democrats four elections in a row. 117.2 million have backed the GOP.

Go here to read the whole thing.