The authors are blunt about how what they observed of Team Clinton behind the scenes was completely different from what most of the public saw:
Over the course of a year and a half, in interviews with more than one hundred subjects, we started to piece together a picture that was starkly at odds with the narrative the campaign and the media were portraying publicly. Hillary’s campaign was so spirit-crushing that her aides eventually shorthanded the feeling of impending doom with a simple mantra: We’re not allowed to have nice things.
Wouldn’t it have been nice to know there was a “feeling of impending doom” inside the Clinton campaign last year?
It’s not that there was no coverage of the campaign’s infighting and stumbles. There just wasn’t much to suggest that the dysfunction of Clinton’s team would prove fatal, or even that it was worse than the usual clashing of egos in a high-stakes national race. The Trump campaign was usually portrayed as an out-of-control clown car, with feuding egos, bumbling incompetence, and campaign managers changing as regularly as Spinal Tap drummers. The Clinton campaign, by comparison, was perceived to be an experienced, well-funded, well-organized, well-oiled machine brimming with dozens of campaign offices in swing states and a proven ground game.