with us now, mulligan, davis for the "new york times" and jim sh sherman, our national correspondent. jim, he was actually the first person who listened to the call to testify, and what you heard on the call was not part of what he had prepared. how significant is this? >> in a few ways, one, his credibility. here is a uniformed member of the military, wounded in iraq, who came out and swore under oath to this testimony. the fact that he has firsthand knowledge of this call, but also the way he describes it. when you look at his testimony, he said there was, quote, no ambiguity, that there was a demand ukraine investigate the bidens in exchange for the white house meeting. this gets at that essential charge here of there being a quid pro quo and vindman testifying, again under oath, that this was not a question, this was not a theory, but that it was made very clear this was connected. the other issue i draw attention to from both hill and vindman's testimony here is the tie directly to the white house. you have fiona hill testifying that gordon sondland, the president's appointee as