White voters were 72 percent of the electorate in 2012, and their share of the population has shrunk a couple points since then. [Donald] Trump has had trouble winning certain segments of the white vote, such as suburban women and college-educated voters.

Donald Trump is a candidate who divided his own party more deeply than any presidential candidate has before.

If [Donald] Trump loses narrowly, it will make it much harder for the GOP to unify. Under that scenario, the Trumpists are likely to argue that the election was lost because the Republican establishment failed to rally around the choice their own voters made.

For a long time, many Republicans thought if they just took two aspirin and laid down, [Donald] Trump would go away.

Does Donald Trump accept the results and concede graciously, pursue legal action, or tell his followers to take to the streets?

The lesson is that voters in both parties are in a very anti-establishment, populist mood. Hillary Clinton is the establishment candidate.

Meanwhile, there are some traditional battleground states - like Ohio and Iowa - that are becoming older, whiter and less educated. That's turning them from true battlegrounds into more reliable red states.