- Mary Trump said the "horrors at the border" led her to speak out against her uncle, US President Donald Trump.
- She made the comments in an interview with MSNBC's Rachel Maddow on Thursday night.
- Her book, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man," has already sold nearly a million copies.
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Mary Trump, the niece of President Donald Trump, thought that her uncle would be surrounded by smart people who would protect him and the country against his "worst impulses," she told MSNBC's Rachel Maddow on Thursday.
"Clearly I was wrong," she said.
"I can't say that there was a last straw because there had been so many straws," the president's niece said. "But certainly the horrors at the border — you know, the separating of children from their parents; the torture, the kidnapping, and the incarceration of them in cages, was unthinkable, unbearable, and when an opportunity presented itself to me to do something, I needed to take a leap."
Mary Trump's book, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man," came out earlier this month, revealing what she claims is a long family history of racism and deceit.
In the interview, Mary Trump was asked if she ever heard President Donald Trump use the N-word or any anti-Semitic slurs.
"Yeah, of course I did," she said. "I don't think that should surprise anybody given how virulently racist he is today."
She also addressed her uncle's response to the coronavirus.
"I want people to understand what a failure of leadership this is," she told Maddow, "and the reason he's failing at it is because he's incapable of succeeding at it."
That, she said, is because President Trump is incapable of admitting a mistake or accepting responsibility.
"More people are getting sick, and more people are going to die," she said. "Instead of taking it seriously, instead of standing aside and letting the experts take over, Donald is hawking black beans. It would be absurd if it weren't so devastating."
In her book, Mary Trump reveals herself as the source who provided The New York Times with Trump family tax documents revealing that the president was not a self-made entrepreneur, but rather heavily subsidized by his father's wealth.
"I think there's a lot more to uncover," she said of the president's taxes.
The Trump administration has flatly denied claims in the book and the claim made by Mary Trump that her uncle used racist and anti-Semitic slurs. The president's brother, Robert, earlier took legal action to prevent it from being published, claiming it violated a confidentiality agreement.
Mary Trump said she's prepared to deal with the fallout of revealing her family's dirty business.
"I'm not scared," she said. I'm taking appropriate precautions, certainly, because I'm not deluded about potential scenarios. He is in a position of great power. I know my family to be quite vindictive, and Donald has a rather passionate following."
"Whatever the consequences are, I'm prepared to deal with them the best I can," she added.
