Harris is prone to tantrums, wants to be treated like a princess, micromanages, fixates on minutia while ignoring the big picture, and sometimes does exactly opposite of what advisers tell her with bad results that they have to clean up later, staff members said.
It's a story that's been told before. When her first campaign staff left in April, the same description of Harris was given by those who quit the effort to unseat Democratic Sen. Bill Nelson.
"That's exactly like what happened," said Ed Rollins, a strategist that left the campaign in April. "Everything is someone else's fault. If there's not a Starbucks coffee house within distance, it's someone else's fault."
Campaign manager Glenn Hodas — the third to work for Harris — confirmed Thursday and four other key staffers are leaving this week, including communications director Chris Ingram, who Wednesday said he was leaving. In addition, field director Pat Thomas and two of her assistants are also leaving. Also, political director Brian Brooks and fundraising assistant Kristen Cochran are walking out the door, according to two campaign sources speaking on condition of anonymity so as to not look disloyal.
Hodas, who will return to his Illinois political consulting business, Hodas & Associates, didn't want to talk about his decision, saying he wanted his departure to be amicable.
Harris was positive in announcing the departures in a press release, which said the campaign was "aggressively moving forward."
"I have thoroughly enjoyed working with Glenn Hodas, Pat Thomas and the other departing staff members. I appreciate their hard work and service on my behalf. I wish each of them the very best in their future endeavors," Harris said.
Thomas will be replaced by Daphnie Ricobene, who worked for state Sen. Burt Saunders' attorney general campaign before he dropped out of the race. Replacements for Hodas and Ingram will be named shortly, the campaign said.
But leaving staff members speaking on condition of anonymity described a work situation that became intolerable. Sure, they had heard that Harris was tough to work for, but they said they thought it couldn't be as bad as described. They ended up finding it worse than they imagined.
This didn't come as a surprise to Rollins, who served as President Reagan's political director and ran Ross Perot's presidential campaign in 1992.
"Katherine is probably the worst micromanager I have ever seen and her instincts are 100 percent wrong," Rollins said. "After a while you say, 'Why am I putting up with this crap?"'
He said Harris was condescending and abusive to Hodas', Thomas' and Ingram's predecessors — Jamie Miller, Megan Ortagus and Morgan Dobbs. She constantly complained about just about everything, Rollins said. Campaign crowds were too small, Nelson was getting more press and speeches weren't right.
"Katherine has her own guest worker program. No one will ever be able to live up to her expectations because it's not a team effort. It's all about her," Rollins said.
Harris' campaign has also faced other problems. Fundraising has been slow, GOP leaders tried to find another candidate, and she has received more attention for her association with a corrupt defense contractor who gave her $32,000 in illegal campaign contributions than she has on issues.
She has pledged to spend $10 million of her own money on the race. She is facing three mostly unknown opponents in the primary — Will McBride, LeRoy Collins Jr. and Peter Monroe — and remains a heavy favorite to win the nomination.
The general election is a different story. She has trailed Nelson by more than 30 points in some polls and even Republican Gov. Jeb Bush has said she can't win.
Harris also faces surgery on Monday to remove an ovarian mass. Rollins suggested with the latest turnover and her health concerns, Harris should bow out of the race.
"There's no good ending here," he said.