At least three people have withdrawn from consideration to lead Sen. Amy Klobuchar s nascent 2020 presidential campaign and done so in part because of the Minnesota Democrats history of mistreating her staff, HuffPost has learned.

Klobuchar, who plans to make an announcement about a potential presidential bid on Sunday in Minneapolis, has spent the past several months positioning herself to run for president. Shes beloved in her state as a smart, funny and personable lawmaker and has gained national attention for her lines of questioning at high-profile hearings.

But some former Klobuchar staffers, all of whom spoke to HuffPost on condition of anonymity, describe Klobuchar as habitually demeaning and prone to bursts of cruelty that make it difficult to work in her office for long.

It is common for staff to wake up to multiple emails from Klobuchar characterizing ones work as the worst briefing or press release shed seen in her decades of public service, according to two former aides and emails seen by HuffPost.

Although some staffers grew inured to her constant put-downs (Its always the worst, one said sarcastically, It was the worst one two weeks ago), others found it grinding and demoralizing. Adding to the humiliation, Klobuchar often ccd large groups of staffers who werent working on the topic at hand, giving the emails the effect of a public flogging.

Senator Klobuchar loves her staff they are the reason she has gotten to where she is today, a campaign spokesperson told HuffPost. She has many staff who have been with her for years including her Chief of Staff and her State Director, who have worked for her for 5 and 7 years respectively and many who have gone on to do amazing things, from working in the Obama Administration (over 20 of them) to running for office to even serving as the Agriculture Commissioner for Minnesota. She is proud of them and the work they have done for Minnesota.

Some people who worked for Klobuchar say they valued the experience: Klobuchar has an unrivaled command of details, puts in long, enthusiastic hours, and simply demands that her office meet those same high standards, several former staffers maintained. Those employees described working for her as a challenge, but an exhilarating one that caused them to grow and perform their best work. They question whether former co-workers who thought she was abusive were falling for sexist stereotypes about female leaders with high standards.