I found that of the 157 full pardons issued by President Bush to date, almost 2/3 went to people whose convictions had occurred more than 20 years before they were pardoned. Only a handful of pardons went to people convicted less than ten years before the pardon. Every single pardon recipient had fully served their sentence years before they were pardoned. Twenty-one of the pardon grants went to people convicted more than 35 years before, and eight of those pardoned were convicted in the 1940s and 50s.
By far the most frequently pardoned offenses are those falling into the general category of theft and fraud. But President Bush has also pardoned 29 drug offenders, 11 people convicted of a firearms-related offense, and eight tax evaders. In addition to the usual complement of bootleggers (11) and car thieves (7), there are teller embezzlers, thieving postal workers, gamblers, illegal dumpers, draft dodgers, and election law violators. The batch also includes the obligatory odometer cheat....
Only 18 of the 157 people pardoned spent more than two years in prison, and 16 of these were convicted of drug offenses. (The other two were an S&L fraudster sentenced to three years, and an armed bank robber sentenced to 12 years’ imprisonment.) Most surprising to me, more than two thirds of those pardoned spent no time in prison at all....
Something else that may be surprising to some, most of those pardoned (113) were not represented by a lawyer. Only one of the five individuals whose sentence was commuted was represented by counsel in connection with his clemency application.
IIRC about four people have had their sentences partially commuted while still serving those sentences, rather than receiving a pardon.
There are a great many people who have the stigma of being classified as a criminal, yet committed only a relatively minor crime long ago. Those pardoned by the President are only the tip of the iceberg. Typically, civil rehabilitation, which many states afford those convicted as a matter of course by an automatic or near automatic administrative device, is sought to allow someone to obtain a license, or be eligible for a job, or own a gun, or vote.
While there is strong evidence that recent crimes are pertinent to an individual's likelihood of recidivism and other negative conduct, there is far less evidence that this is relevant in the case of decades old crimes.