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.

If Donald Trump wins, it will be a seismic event.

The aftermath of this extraordinary election [2016] could be just as surprising as the race itself.

African-American voters are not nearly as enthusiastic about [Hillary] Clinton as they were about [Barack] Obama.

[Donald Trump ] would make history in so many ways because he is a candidate who eschewed the traditional arts of political campaigns, including field organization, traditional advertising, debate preparation and policy knowledge.

Republicans think that [Ted] Cruz would be like Barry Goldwater. He'd lose in a landslide and pull the party down with him. They'd lose Senate and House seats.

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.