It seems more tapes have become available to the public, which cast the former president in an even more sinister light. Ken Hughes is the author of the most recent book on Nixon, Chasing Shadows. You can read an excerpt here. David Greenberg reviews both the book and the documentary for the Washington Post. Hughes apparently focuses largely on the Chennault Affair, in which Nixon used a friend of a friend to sabotage Johnson's attempt to end the Vietnam War in 1968, as Nixon feared it would give Humphrey a boost in the tight election. Eerily similar to Reagan's own efforts to sabotage Carter's attempt to end the Iran Hostage crisis in 1980, but the Gipper seemed to skate clear of this controversy. Hughes doesn't let Nixon off the hook.
It seems that this kind of skulduggery has become part and parcel of the Republican bag of dirty tricks. Of course, Nixon wasn't the first to resort to such nasty deeds to get what he wanted, nor are such dirty tricks exclusively Republican. Johnson was certainly no saint, and no doubt saw any kind of peace agreement in Vietnam as a way to undermine Nixon's candidacy. But, what sets Nixon apart from others is that he didn't seem to have a single altruistic bone in his body. He was perhaps the most cynical and duplicitous president ever, undermining the efforts of his own cabinet, notably Henry Kissinger, who the former president thought was straying from the path.
Nixon comes across as a later day Richard III. As much as Buchanan tries to point to the good Nixon did, the bad just piles up against him, made even worse by Nixon's copious tapes, which ultimately proved his undoing and still haunt his battered legacy 40 years after.