Even if [Donald] Trump concedes, some of his supporters have promised to take up arms against [Hillary] Clinton.

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.

You have [Donald] Trump and [Ted] Cruz battling it out, and the moderate establishment candidates like Chris Christie or Jeb Bush, Marco Rubio, John Kasich - they have formed a circular firing squad.

If [Hillary] Clinton wins, history will also be made: She would be the first female U.S. president, of course, but also the only candidate in the modern era, other than George H.W. Bush, who managed to follow a two-term president of her own party.

The [Hillary] Clinton campaign's recent travel schedule shows how seriously it takes this problem. She and her surrogates have held rallies in cities like Philadelphia, Detroit and Cleveland, trying to boost turnout among African-Americans.

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

If [Hillary] Clinton can come close in those two traditionally red states, it will be because of the diverse, educated populations around Atlanta and Phoenix. And it will be a sign that Arizona and Georgia are on their way to becoming the new battleground states.