Tony Schwartz, Donald Trump's co-author on the 1987 book "The Art of the Deal," feels a "deep sense of remorse" for contributing to the business mogul's popularity, saying there is "an excellent possibility" that a Trump presidency would lead to the end of civilization.
In this June 7, 2016, file photo, Republican presidential candidate Donald Trump gestures to supporters as he leaves the stage with his wife Melania after a news conference at the Trump National Golf Club Westchester in Briarcliff Manor, N.Y.(AP Photo/Mary Altaffer)
Donald Trump invited a backlash when accusing Mexico of sending rapists and criminals across the border and proposing to temporarily ban Muslims from entering the country as a way to prevent terrorism. However, Mr. Trump could have expected Democrats to label him a racist regardless of what he said or did. (Associated Press)
In this July 12, 2016 photo, Indiana Gov. Mike Pence joins Republican presidential candidate Donald Trump at a rally in Westfield, Ind. Over the past two decades, Trump has disagreed with his vice-presidential pick on plenty of political issues, including immigration policy, entitlement programs and trade. On social issues above all, Trump and Pence arrive at the 2016 general election from very different paths. (AP Photo/Michael Conroy, File)
In this Feb. 6, 2016, file photo, Ohio Gov. John Kasich, left, and Donald Trump, right, speak to reporters after a Republican presidential primary debate hosted by ABC News at Saint Anselm College in Manchester, N.H. (AP Photo/Matt Rourke, File)
Republican National Committee Chairman Reince Priebus failed Thursday to strike a deal with renegade delegates, who want to free up "bound" delegates in an effort to thwart Mr. Trump's nomination.
Supporters of Republican presidential candidate Donald Trump wait for the start of a rally in Westfield, Ind., Tuesday, July 12, 2016. Trump is wildly unpopular among young adults, in particular young people of color, and nearly two-thirds of Americans between the ages of 18 and 30 believe the presumptive Republican nominee is racist. That’s the finding of a new GenForward poll that also found just 19 percent of young people have a favorable opinion of Trump compared to the three-quarters of young adults who hold a dim view of the New York billionaire. (AP Photo/Michael Conroy)
FILE - In thus July 11, 2016 file photo, Republican Presidential candidate Donald Trump speaks in Virginia Beach, Va. (AP Photo/Steve Helber, File) *FILE**
In this Thursday, June 30, 2016, file photo, Republican presidential candidate Donald Trump speaks at a town hall-style campaign event at the former Osram Sylvania light bulb factory in Manchester, N.H. (AP Photo/Robert F. Bukaty, File)
In this March 21, 2016 photo, former House Speaker Newt Gingrich leaves after a closed-door meeting with Republican presidential candidate Donald Trump, in Washington. Trump has narrowed down his vice presidential shortlist to a handful of contenders. While the presumptive GOP nominee is known for throwing curveballs, here's a look at some of the men and women he is said to be considering: Gingrich, Chris Christie, Mike Pence, and others. ( AP Photo/Jose Luis Magana, File)
Donald Trump appeared to be angling for a political boost no matter what the FBI recommends. If Hillary Clinton is indicted, she might be nudged out of the race. If she isn't, he can cry malfeasance. "Like I said, the system is totally rigged!" he said on Twitter. (Associated Press)
Republican presidential candidate Donald Trump speaks at a town hall-style campaign event at the former Osram Sylvania light bulb factory, Thursday, June 30, 2016, in Manchester, N.H. (AP Photo/Robert F. Bukaty)
Republican presidential candidate Donald Trump speaks during a campaign stop, Tuesday, June 28, 2016, at Alumisource, a metals recycling facility in Monessen, Pa. (AP Photo/Keith Srakocic)