President Trump’s re-election campaign said Monday that it is preparing to sue former White House staffer Cliff Sims for violating his non-disclosure agreement in his new tell-all book about his experience in the White House. “The Trump campaign is preparing to file suit against Cliff Sims for violating our NDA,” Michael Glassner, the chief operating officer for the Trump 2020 campaign, tweeted Tuesday morning. President Trump called Sims a “gofer” whom he hardly knew in a tweet, all while the author was live on CNN. The book, Team of Vipers: My 500 Extraordinary Days in the Trump White House, includes a number of new revelations. Sims responded to Trump’s Twitter attacks on-air: “My identity is not wrapped up in being a Trump staffer... It doesn’t matter to me what Donald Trump or anyone else says I am.”