A former aide to former National Security Adviser John Bolton said Bolton “let down” the country by not providing Congress with information from his forthcoming book—on President Trump’s supposed quid pro quo with Ukraine—during the impeachment process. “You’ve let down your country. I worked loyally for you for 15 years,” Mark Groombridge tweeted on Monday. “Yes, the Senate was never going to convict, but you had the opportunity to provide them with the info so they could make a fully informed decision. Guess it was about book sales after all.” Details from Bolton’s new book about the Trump administration’s effort to get Ukraine to investigate former Vice President Joe Biden and his son surfaced in the media in recent weeks, including the claim that Trump personally asked Bolton to help with the Ukraine pressure campaign last year. The reported claims raised questions about whether additional witnesses should be called in the Senate impeachment trial. However, lawmakers voted against calling witnesses. Groombridge previously told NPR that testimony from Bolton would “shed light on the disorder in the White House.”