Commutations Are Questionable

My new column is up today.  It discusses the questionable state and federal executive power of granting clemency.  Why should one politically motivated operator be able to overrule an entire justice system?  I say he shouldn't.  
 
Commutations, in and of themselves, are questionable - if evidence is strong enough for a commutation, shouldn't it be strong enough for a pardon?  Anything less is leaving an "innocent" man in jail, or simply using authority to overrule a sentence declared by the people.  Pardons are more absolute, but still questionable - just witness Marc Rich or President Nixon.