Innocent people don't resign the presidency and they don't fire the investigator that's investigating them and their staff on a Saturday night and try to get away with it. That's not what innocent people do.
He had a good, solid 6 years of continuous combat with the Left and the press - it shouldn't be too surprising that this was just another fight to him.
You really think that talking about possibly supporting the Watergate defendants compares to LBJ's hash of the Vietnam War, JFK's three near-nuclear war confrontations/assassinations of world leaders, Carter's idiotic trashing of our intelligence agencies/defense department, Clinton's venalities and policy failures..etc.,etc.?
Nixon fired Cox because Cox was Ted Kennedy's hatchet man who was uninterested in indicting the Watergate consprirators and far more interested with investigating every inch of the White House, using every unethical means possible.
Nixon resigned because he recognized that the coup had been played to an indefensible end and he valued the presidency too much to put the country through an impeachment.
Contrast that with "Loverboy" Clinton's performance.