He had a good reputation until June 17th, 1972 when 5 burglars underwent 'Mission Impossible' and proceeded to break into the Democratic National Committee headquarters at the famous Watergate hotel and stole information, bugged the offices to overhear conversations going on. This was a big deal but it didn't strike heavy controversy until the evidence linked to Nixon's staff and found they were covering this up.
Carl Bernstein and Bob Woodward were the chief architects that were bold and courageous enough to follow the evidence and it was their reporting and investigating that led to the mainstream attention Nixon's office was now getting.
This left the nation angry yet torn on the issue, because Nixon was widely admired and heavily supported, but they even caught him on tape in the 'Smoking Gun' tape where he was making legitimate attempts to cover up the break-in and made plans to have the CIA falsely claim to the FBI that national security was involved, and to block them out of the investigations.
This was a huge deal because it opened some people's eyes as to the corruption going on in politics and how dirty the game was, and the aftermath of the Watergate scandal led to the the ultimate resignation of the President of the United States, also 69 trials occurred in which 48 led to convictions and incarcerations. Campaign finance and political reform was heavy in midst of this scandal and it changed the dynamic of politics as they knew it.
Nixon was and still is the only person to have ever resigned as President of the United States.
|\President Nixon's resignation of the office of Presidency after Watergate|
Link to article: http://watergate.info/