John Dean was White House Counsel to President Richard Nixon and became deeply involved in events leading up to the Watergate burglaries and the subsequent Watergate scandal cover-up. Despite his initial involvement, Dean became a key witness for the prosecution and was the first administration official to accuse Nixon of direct involvement with Watergate and the resulting cover-up. His accusations were confirmed when the secret White House tape recordings were made public. Dean's cooperation with the investigation led to a reduction in his prison time.

But for Dean blowing the whistle on Nixon's misdeeds it is highly questionable whether the Watergate scandal would have resulted in Nixon's resignation.