Here's the relevant text from Ford's Pardon of Nixon:
"Now, Therefore, I, Gerald R. Ford, President of the United States, pursuant to the pardon power conferred upon me by Article II, Section 2, of the Constitution, have granted and by these presents do grant a full, free, and absolute pardon unto Richard Nixon for all offenses against the United States which he, Richard Nixon, has committed or may have committed or taken part in during the period from January 20, 1969 through August 9, 1974."
Again, he was gone. Hillery is just getting started toward the POTUS. 0bama giving her a get out of jail card is obstruction of justice, and smacks of payola. He can be prosecuted himself.