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.

Many people feel he did cross a line in a way he hadn't even done before and also that Republicans had to speak out because they believe Trump poses a danger to the party.

There's disgust with what people called a broken political system, and they're really angry at elites, whether it's the Republican establishment or particularly the media who they feel look down on them, tell them they're bigots.

[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?

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

Senate races have tightened along with the presidential race. Watch to see how many Republican Senate candidates outperform Donald Trump - and how many hang on to their seats in states that he loses.

Democrats came into the race with a structural advantage in the Electoral College. Their big blue wall - the states that Democrats have won in the past six presidential elections - gave [Hillary] Clinton a strong base to build on.