@Real Music,
Oralloy has already responded that a
preemptive pardon can be issued.
While it certainly doesn't look good for the person pardoned, it doesn't mean that they are guilty of anything. Such pardons can be extended to spare someone the president knows or believes is innocent of wrongdoing and who he feels should be spared the ordeal and expense of a criminal proceeding. He might also do so (as in the case of Ford) to spare the country from a very ugly, and divisive spectacle; particularly when the pardoned person has already been justly and harshly punished. Nixon's resignation broke him and I'm sure plagued him every day for the rest of his life.
There was, at one point, talk about Obama issuing a pardon of Hillary Clinton in anticipation of the possibility that Trump would make good on his campaign rhetoric about having her prosecuted if he were elected. I don't know if Obama every really gave it serious thought, but there was also speculation about Clinton refusing any offer of a pardon as it would be the final coffin nail for her moribund political career.