"She is so nasty to agents that being assigned to her detail is considered a form of punishment," said Ronald Kessler, author of The First Family Detail, which pulls back the cover on the private lives of some of the most powerful people in the country.
Kessler, a veteran journalist with more than 20 books about the FBI, presidents, the CIA and of course, the Secret Service to his name, says the former first lady's treatment of her protection detail says a lot about who she is.
"It shines a light on her character," he said. "She claims to be a champion of the little people, and she's going to help the middle class. And, in fact, she treats these people around her, [who] would lay down their lives for her like sub-humans; and I think voters need to consider that."
But just being kind isn't enough to get the good will of agents, Kessler says he learned.
Vice President Joe Biden is "very nice to agents," Kessler said, but he exhausts his security detail making last-minute trips homes to Delaware, and has a "habit of swimming in his pool nude."
"He likes to skinny-dip both at the pool at his vice president residence in Washington and his home in Wilmington, and female agents are very offended by that," Kessler said. "And, in fact, you could make a case that it's almost sexual harassment."
Kessler's revelations go beyond the details of the lives of the protectees, writing that the agency's success record is more luck than preparation.
"Agents tell me that it's a miracle there has not been an assassination, given all this corner-cutting," Kessler said
"[An] example in the book is that, when Bradley Cooper went to the White House Correspondents' Dinner, a high-ranking Secret Service official told the detail at the Washington Hilton, 'Just let him in with his SUV' -- in this secure area where only Secret Service cars are allowed, and even they have to be screened for explosives. He was not screened; someone could have put explosives in."
The book, released last week, has been met by a wall of criticism, accusing Kessler of peddling false information.
Secret Service spokesman Ed Donovan called the book "intellectually lazy and riddled with inaccuracies."
"We currently dedicate more personnel, funding and technical assets to our protective mission than at any time in our history and our protective measures and methods continue to increase in scope and complexity, not diminish," Donovan said in a written statement. "Comments attributed to our personnel, current or former, regarding their personal perceptions of Secret Service protectees, are just that -- their personal perceptions -- and should not be discussed in any forum."
The Clintons rereleased a joint statement slamming Kessler's book, along with two others published in recent months.
"We now have a Hat Trick of despicable actors concocting trashy nonsense for a quick buck, at the expense of anything even remotely resembling the truth," a spokesman said on behalf Bill, Hillary and Chelsea Clinton. "It's an insult to readers [and] authors, and should be reserved for the fiction bin, if not the trash."
"Their behavior should neither be allowed nor enabled, and legitimate media outlets who know with every fiber of their being that this is complete crap should know not to get down in the gutter with them and spread their lies," the statement continued. "But if anyone isn't sure, let's strap all three to a polygraph machine on live TV and let the needle tell the truth."
The harsh words weren't limited to those criticized inside Kessler's pages. Marc Ambinder, an editor at This Week magazine, said the book has "a surprising number or weird inaccuracies that should lead Kessler to question the judgement of some of his own sources."
"Too often, Kessler seems to have listened to his sources, written their words down, and then simply printed as fact their allegations or observations without checking on them," Ambinder said. "I find that weird."