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

There was tremendous animus to President [Barack] Obama. Many of people said he was un-American, not a Christian and worse.

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

Michael Rubio said Trump's plan was impulsive and not well thought out. The other thing that's really annoying Republicans is that this was supposed to be their great week. The president gave a speech on terrorism that was not well received. They were working hard to tie Hillary Clinton to the president. Then along comes Donald Trump, and the story changes dramatically.

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

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.

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.