Trump's 2020 campaign suing ex-aide over explosive book

President Donald Trump's 2020 presidential campaign filed for arbitration Tuesday against Omarosa Manigault Newman over what it said is her violation of a 2016 non-disclosure agreement.

The legal action was filed with the American Arbitration Association in New York City, according to multiple reports.

The suit comes on the day Manigault Newman releases her tell-all memoir, Unhinged: An Insider's Account of the Trump White House, which details the president's life behind closed doors.

Manigault Newman served as Trump's director of communications until she was fired by Chief of Staff John Kelly in December 2017. Her book chronicles her time in the White House, and includes salacious allegations about the president and his closest confidants.

Trump has fumed privately and publicly over the book, and on Tuesday launched into a Twitter screed that assailed Manigault Newman as a "dog," among other derogatory terms. Manigault Newman is black.

"When you give a crazed, crying lowlife a break, and give her a job at the White House, I guess it just didn't work out. Good work by General Kelly for quickly firing that dog!" Trump said on the microblogging site.

Trump's deeply divisive rhetoric drew a stern rebuke from many, including outgoing Republican Senator Jeff Flake.

"This kind of language is unbecoming of a President of the United States. There is no excuse for it, and Republicans should not be okay with it," Flake, who has repeatedly butted heads with the president, said on Twitter.

Manigault Newman had worked with Trump for 15 years before her stint in the White House, including during Trump's time as a reality television star, and during his presidential campaign.