How Nixon Helps us Imagine the Worst

'Although Nixon's responsibility for Vietnam is large and for Watergate central, he could be forgiven for not entirely understanding the convulsions he had visited upon politics and the presidency. As a result of his actions, presidents not only would be subject to doubt and second guessing, they would be suspected of outright criminality. Nixon's tapes of his office and the telephone conversations left an irrefutable historical record that the president abused government power for political purposes, obstructed justice and ordered his aides to do so as well. Watergate ended with unusual clarity and unusual closure because Nixon resigned. The scandal left a series of obvious questions that would come to plague his successors. Could another president be a criminal? Did presidents talk and plot in private like Nixon? Would another president have to resign?'

--From the introduction to Bob Woodward's Shadow, a book about the toxic legacy Watergate left on each of Nixon's successors.