demanding in return an investigation into joe biden and his son. democrats first witnesses, two career civil servants seated together for the entire day, bill tayloring temperature top american diplomat in ukraine saying he was told everything depended on ukraine publicly announcing these investigations. as taylor put it behind closed doors, that was my clear understanding, security assistance money would not come until the president of ukraine committed to pursue the investigation. george kent was in charge of ukraine policy and was concerned about politically motivating prosecutions. he was told the prosecution wanted nothing less. even in extraordinary times, this will be an extraordinary day. congressional reporter phil mattingly has more on capitol hill. christine and dave, here we