Reason. The real reason in my opinion is nixon was trying to get whatever evidence the government had of his own wrongdoing. One of the aids told him there was a report on the bombing that was in the hands of prominent democrats who were working at the Brooking Institute and the washington think tank. Nixon is furious and orders a break in the Brooking Institution in order to get the report. That is on tape. It is the only breakin we know that he ordered for sure because he ordered it on tape several times. In order to get this accomplished, he put together the special Investigation Unit and a former fbi agent and cia agent and people wondered about the coverup because as far as we know he didnt order that. If he had not ordered a coverup, a full investigation on the crimes would lead back to the breakin that nixon did order and that would lead back to the shell defense and sabotage the 1968 campaign. So people say about watergate it isnt the crime but the cover up but it is the cover