explain why indeed there is no prosecution as a result of this. how unusual it is. because of a memo that's bb there since 1973. in the department of justice. about prosecuting a president. he'll walk through that. and explain why he couldn't just say there's nothing here. there is a lot of evidence that there was an effort by the president to obstruct this investigation. and what obstruction of justice really means. he's seasoned and able witness. >> you mention 1973. you staid. you testified against nixon in 1973. you were subpoenaed. they're calling this a friendly subpoena. if so was it a friendly subpoena? >> i don't think it is. i actually had a friendly subpoena. when i testified before the senate. in this situation i know from my own testimony in working with