Ambrose's Nixon: Ruin and Recovery 7

In this blog post, I'll highlight two passages from Stephen Ambrose's Nixon: Ruin and Recovery, 1973-1990.  We're in the Watergate scandal, and President Richard Nixon's former counsel, John Dean, has testified before Congress that Nixon engaged in a cover-up and obstruction of justice regarding the break-in of Republicans into the Democratic National Committee's headquarters at the Watergate hotel.  Dean was saying that Nixon was specifically trying to obscure the possible connection of that burglary with high officials in the White House.

1.  On page 194, Ambrose says: "To most Americans, the distinctly different reactions of Nixon and [John] Dean answered the question, Who was telling the truth?  Dean wanted the tapes played, in full, in public.  Nixon wanted the tapes to be kept sealed within the White House, where he could continue to make selective use of them."

Nixon recorded his conversations within the White House, and so there were tapes.  According to Ambrose, Dean called for the tapes to be played in full, whereas Nixon only wanted to make selective use of them to exonerate himself.  That sounded fishy to most Americans, Ambrose narrates.  My understanding of Ambrose is that Nixon could have destroyed the tapes before they were subpoenaed, since they were his own property.  After the tapes related to Watergate were subpoenaed, however, it was a different story.
2.  Nixon gave a speech about Watergate, and, on page 209, Ambrose states:

"Nixon claimed in his memoirs that the speech 'hit a responsive chord.  The numbers of telegrams and phone calls to the White House immediately after it was over were the biggest since the says of my Vietnam speeches.  People were tired of Watergate.'  Many of those calls and telegrams were manufactured by his own aides, as they always did after a major speech.  It gave the boss a boost to see the telegrams stacked on his desk."

Ambrose actually makes this point about the telegrams more than once, largely in volume 2 of his Nixon trilogy.  Were these aides manufacturing the telegrams, as in making up people?  Or were they contacting people who were largely sympathetic to Nixon and asking them to send telegrams, to make Nixon feel better and to give the aura of widespread support for Nixon?