Gerald Ford Pardoned Richard Nixon....But Nixon PERPETUATED no crime. He never did what he was accused of (by Hillary, by the way). He left to stop the damage to the U.S. from further embarrassment. His only crime was he successfully prosecuted, and jailed, Alger Hiss. He was accused of thinking about crimes that Odumbo has done often.
Ford's pardon of Nixon was mentioned as an example of a 'preemptive pardon'. What you have said may be true, but that does not change the fact of Ford's issuance of a pardon to him.