Mitt Romney got 59 percent of the white vote in 2012, considered by many to be a high-water mark with this demographic group. Can [Donald] Trump win a higher share of white voters than Romney and get more of them to turn out?

Well, it's possible that the new infusion of ad money against Donald Trump kept his margins in Kentucky and Louisiana down a bit. But we're also seeing something that we've never seen in 100 years, which is we are seeing the crackup of a major American political party.

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.

On the other side, you have the conservative intelligentsia - magazines like National Review, which has a big anti-Trump issue; Weekly Standard editor, conservative talk show hosts - they're mounting a big anti-Trump effort, pro-Cruz effort because they think [Donald] Trump is dangerous and he's not qualified to be commander in chief.

If [Hillary] Clinton can't boost African-American turnout, even with all that help, the question becomes whether she can make up for it with historic levels of support from Hispanics and suburban women.

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

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