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.

The Republican Party, right now, is a conservative populist party.

Jeb Bush was supposed to be the establishment candidate, but he didn't catch on. And the extraordinary thing about this Republican primary is that the establishment, moderate wing of the party has sidelined itself. They're not coalescing around one candidate as they have in the past.

[Donald] Trump has said he will accept the results of the election - if he wins. And he has said the only way he can lose the election is if it's stolen from him. Weeks before any votes were cast, he was predicting widespread voter fraud. So if he loses, what does he do?

If they can get 15 or higher, it will be a very bad night for House Speaker Paul Ryan. Ryan twisted himself into a pretzel by endorsing but not always supporting Donald Trump. Now, he's facing the prospect of a slimmer majority, with fewer moderates. Conservative members in the Freedom Caucus have already sent warning shots threatening Ryan's tenure as speaker.

The enthusiasm for [Donald] Trump had gone up. The net result was it made people more supportive of him.

Hillary Clinton is also not a very exciting, inspiring candidate to a lot of the left-leaning Democratic base, especially in Iowa.