>> isn't that what you do to people under mine the credibility of a witness? it's hard to do with this. >> it's what people do when they're desperate and know the evidence is mounting. >> "new york times" reports bolton drafted a memo in august that sought to restart the $391 million and the aid package. trump refused to sign it. according to documents reviewed be by the time. could we learn from vindman how the decision to with hold money was made? >> it sounds like he would have that information. also the importance of john bolton as a witness. clearly he knew this was going to be a big issue. he wrote a memo. he's trying to paper it up and make a record. bolton by a potentially an explosive witness against trump. >> juliette, here's more. i realize if ukraine pursued a an investigation it would be entrepted into a partisan play.