know in my own head precisely what i did and why i did it. >> okay. >> and i know that i made some mistakes. i deeply regret those mistakes. >> as richard nixon's right-hand man he was the one most often recorded on the tapes, and they destroyed him. >> i had the rare privilege for four years serving on the white house staff under one of the greatest presidents. >> chief of staff hr haldeman found guilty on the watergate trial. >> do you regret what happened and what you did? >> oh, sure. the country lost motion, a lot of the good things we were working on in the way of domestic reforms were lost in the mess. you can't help but regret aftermath of that. a lot of good people had their lives spoiled in the process.