testimony. what is the impact? >> it's huge. test the first white house official to testify here. we have heard from defense department officials. this is the first time this reached the white house. and it's almost like the layers of an onion getting peeld back. a few days ago we had the president implicated for the first time. obviously the initial call memo. a few weeks ago. for the first time a witness pointed directly at the president being involved. so it will be significant that a white house staffer is going to speak up here. >> so listen, he listened directly to the july 25 phone call between the president and the president of ukraine. taylor said in opening statement that he told him the call could have been better. will we learn more than what's in the transcript? >> it's hard too tell. at least we'll have context. what we're really witnessing taking place in the white house