When Mark was a small boy, his father pointed to Richard Nixon on television and said "look, it's the devil."
Then when Mark was 12, his dad took him to see All The President's Men, despite it being a AA certificate. This cemented the younger Kermode's view of the Earthly personification of Satan, at least until a certain big-haired director started nefariously injecting his giant robots hitting each other movies into the world.
Part of the book Mark wrote about The Shawshank Redemption draws on the parallels between the warden of Shawshank prison and Nixon; it is notable that the final events of Shawshank take place during the end of Nixon's time in office.
Sir Anthony Hopkins played Nixon in Nixon, and although despite nothing like him, Mark felt the portrayal was brilliantly done - Hopkins getting all the movies and gestures exactly right.
Frank Langella also played Nixon in Frost/Nixon, and although his performance was terrific, Mark was annoyed that Michael Sheen's performance opposite him as David Frost did not garner equal attention, as it was just as good. Mark also noted that he had met former BBC director-general John Birt once and had he known then that Birt had a key role in the interview (as shown in the film), he would have asked Birt about the time he met Nixon. Mark mused that it was sad it would now never happen.