>> our role in the senate select committee was to make disclosures through televised hearings. we had the power of subpoena, the power to put people under oath. >> but congress does not have a prosecutorial function. it's only to investigate, to legislate, and to inform. >> by march of 1973, you had the senate select committee pushing for hearings. >> but nixon by and large did not want his aides to testify. >> people were very interested in the senate hearings and whether nixon was going claim executive privilege to keep his top aides from testifying. >> a president can't use executive privilege to shield his own criminal conduct. >> nixon was under pressure of republicans, and many voters who had voted for him in '72 to cooperate.