Sam Wang also has an interesting chart up right now on different groups of the electorate and how they have become polarised since 1996:

election.princeton.edu

African-Americans, no religion, and white college grads have moved strongly for the Democrats, while Evangelicals and white non-college grads have move strongly to the GOP.

As a white non-college grad, I have been left behind. Do I still have a place in the Democratic Party? /s